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Appl Environ Microbiol, 1976 Mar, 31(3), 399 - 403 Microbial formation and degradation of dimethylamine; Tate RL 3rd et al.; Dimethylamine was formed from trimethylamine in soils of different pH values . The rate of disappearance of the secondary amine from soil was affected by pH and was markedly reduced under anaerobiosis . The accumulation of dimethylamine in cultures of Micrococcus sp . provided with trimethylamine depended on the nitrogen sources available to the bacterium but was not greatly influenced by the C-N ratio of the medium . Dimethylamine and nitrite accumulated in large amounts at pH 6.0 to 8.0 in cultures containing the tertiary amine and nitrate, but dimethylnitrosamine was apparently not produced. Eur J Biochem, 1976 Mar 1, 62(3), 613 - 7 Membrane-reversible H+-ATPase from Micrococcus lysodeikticus; Mileykovskaya EI et al.; Treatment of phosphorylating fragments of bacterial membrane from Micrococcus lysodeikticus with trypsin leads to increase ATPase activity . As a result of this treatment, the membrane fragments acquire the ability to transform the ATP energy into transmembrane difference in potential . Dithiothreitol has a similar effect to that of trypsin on the membrane fragments from M . lysodeikticus . Dicyclohexylcarbodimide inhibits ATPase of the membrane fragments of M . lysodeikticus, and also the ATPase-reaction-coupled generation of membrane potential . It has been suggested that the increased ATPase activity of membranes from M . lysodeikticus during treatment with trypsin and dithiothreitol is connected with the effect of these agents on the protein inhibitor of ATPase. Biochim Biophys Acta, 1976 Feb 18, 425(1), 84 - 94 Structure of eukaryotic chromatin . Evaluation of periodicity using endogenous and exogenous nucleases; Keichline LD et al.; DNA isolated from (a) liver chromatin digested in situ with endogenous Ca2+, Mg2+-dependent endonuclease, (b) prostate chromatin digested in situ with micrococcal nuclease or pancreatic DNAase I, and (c) isolated liver chromatin digested with micrococcal nuclease or pancreatic DNAase I has been analyzed electrophoretically on polyacrylamide gels . The electrophoretic patterns of DNA prepared from chromatin digested in situ with either endogenous endonuclease (liver nuclei) or micrococcal nuclease (prostate nuclei) are virtually identical . Each pattern consists of a series of discrete bands representing multiples of the smallest fragment of DNA 200 +/- 20 base pairs in length . The smallest DNA fragment (monomer) accumulates during prolonged digestion of chromatin in situ until it accounts for nearly all of the DNA on the gel; approx . 20% of the DNA of chromatin is rendered acid soluble during this period . Digestion of liver chromatin in situ in the presence of micrococcal nuclease results initially in the reduction of the size of the monomer from 200 to 170 base pairs of DNA and subsequently results in its conversion to as many as eight smaller fragments . The electrophoretic pattern obtained with DNA prepared from micrococcal nuclease digests of isolated liver chromatin is similar, but not identical, to that obtained with liver chromatin in situ . These preparations are more heterogeneous and contain DNA fragments smaller than 200 base pairs in length . These results suggest that not all of the chromatin isolated from liver nuclei retains its native structure . In contrast to endogenous endonuclease and micrococcal nuclease digests of chromatin, pancreatic DNAase I digests of isolated chromatin and of chromatin in situ consist of an extremely heterogeneous population of DNA fragments which migrates as a continuum on gels . A similar electrophoretic pattern is obtained with purified DNA digested by micrococcal nuclease . The presence of spermine (0.15 mM) and spermidine (0.5 mM) in preparative and incubation buffers decreases the rate of digestion of chromatin by endogenous endonuclease in situ approx . 10-fold, without affecting the size of the resulting DNA fragments . The rates of production of the smallest DNA fragments, monomer, dimer, and trimer, are nearly identical when high molecular weight DNA is present in excess, indicating that all of the chromatin multimers are equally susceptible to endogenous endonuclease . These observations points out the effects of various experimental conditions on the digestion of chromatin by nucleases. Mol Cell Biochem, 1976 Feb 16, 10(2), 67 - 76 Membrane adenosine triphosphatase of Micrococcus lysodeikticus . ISolation of two forms of the enzyme complex and correlation between ezymatic stability, latency and activity; Carreira J et al.; Two new forms of the plasma membrane ATP-ase of Micrococcus lysodeikticus NCTC 2665 were isolated from a sub-strain of the microorganism by polyacrylamide gel electrophoresis . One of them had a mol.wt of 368,000 and a very low specific activity (0.80 mumol.min-1.mg protein-1) that could not be stimulated by trypsin . This form has been called B1 (strain B, inactive) . If the elctrophoresis was carried out in the presence of reducing agents (i.e., dithiothreitol) and the pH of the effluent maintained at a value of 8.5 another form of the enzyme was obtained . This had a mol.wt of 385,000 and a specific activity of 2.5-5.0 mumol.min-1.mg protein-1 that could be stimulated by trypsin to 5-10 mumol.min-1.mg protein-1 . This preparation of the ATPase has been called from BA (strain B, enzyme active) . The subunit composition of both forms has been studied by sodium dodecyl sulphate and urea gel electrophoresis and compared to that of the enzyme previously purified from the original strain (form A) . The three forms of the enzyme had similar beta and delta subunits, with mol.wt of about 50,000 and 30,000 dalton, respectively . They also had in common the component(s) of relative mobility 1.0, whose status as true subunit(s) of the enzyme remains yet to be established . However, subunit alpha, that had a mol.wt of about a 52,500 in form A (ANDREU et al . Eur . J . Biochem . (1973) 37, 505-515), had a mol.wt similar to beta in form B1 and about 60,000 in form BA . Furthermore BA usually showed two types of this subunit (alpha' and alpha") and an additional peptide chain E) with a mol.wt of about 25,000 dalton . This latter subunit seemed to account for the stimulation by trypsin of form BA . Forms BA could be converted to B1 by storage and freezing and thawing . Conventional protease activity could not be detected in any of the purified ATPase forms and addition of protease inhibitors to form BA failed to prevent its conversion to form B1 . The low activity form (B1) was more stable than the active forms of the enzyme and also differeed in its circular dichroism . These results show that M . lysodeikticus ATPase can be isolated in several forms . Although these variations may be artifacts caused by the purification procedures, they provide model systems for understanding the structural and functional relationships of the enzyme and for drawing some speculations about its function in vivo. Experientia, 1976 Feb 15, 32(2), 257 - 9 A method for automatic recording of serum lysozyme activity with the fragiligraph; Resnitzky P et al.; A quick and simple method for the estimation of lysozyme activity using the Fragiligraph, was described . Diminution of turbidity in a suspension of Micrococcus lysodeikticus produced by the addition of standard lysozyme (hen egg white) or serum sample, was continuously recorded for 5 min by the Fragiligraph . The normal mean serum lysozyme activity value obtained by this method is 6,80 mug/ml +/- 1.85. Biochim Biophys Acta, 1976 Feb 5, 418(3), 321 - 9 DNA synthesis and repair in permeable cells of Micrococcus radiodurans; Kitayama S et al.; Cells permeable to deoxyribonucleoside triphosphate were prepared from Micrococcus radiodurans, and DNA synthesis and rejoining of strand scissions induced by gamma-rays were investigated . DNA synthesis was stimulated by ATP at an optimal concentration of 1mM . This reaction requires four deoxyribonucleoside triphosphates and MgCl2 . NAD inhibited the reaction, but no rejoining of primer DNA was observed . Even in the presence of NAD, DNA which was synthesized in the unirradiated permeable cells had a peak molecular weight of only 1.3 - 10(6) . DNA synthesis was stimulated by irradiation of the permeable cells with gamma-rays, but this stimulatory effect was eliminated by the addition of NAD . Both primer and synthesized DNA in the irradiated permeable cells were rejoined in vitro in the presence of NAD and deoxyribonucleoside triphosphates, while those in the unirradiated permeable cells were not rejoined. J Bacteriol, 1976 Feb, 125(2), 509 - 17 Peptidoglycans synthesized by a membrane preparation of Micrococcus luteus; Pellon G et al.; By incubation of cell-free particulate preparations from Micrococcus luteus with nucleotidic precursors uridine 5'-diphosphate-N-acetylglucosamine and uridine 5'-diphosphate-N-acetylmuramic acid-L-Ala-D-iso-Glu-L-Lys-D-Ala-D-Ala, several types of peptidoglycans were obtained: soluble peptidoglycan, insoluble peptidoglycan bound to the membrane and solubilized by trypsin, and peptidoglycan, which remained insoluble after the action of trypsin . The structure of each type of peptidoglycan was studied by action of lytic enzymes and separation of the fragments on Sephadex . Soluble peptidoglycans consist of a mixture of un-cross-linked polymers of various molecular weights . Trypsin-solubilized peptidoglycans are also a mixture of polymers of various sizes . They contain a preponderance of un-cross-linked material and some bridges with dimer peptides . Insoluble peptidoglycans, after the action of trypsin, contain about 50% of un-cross-linked peptide residues; in the other moiety, peptide units are cross-linked by D-Ala leads to L-Lys and D-Ala leads to L-Ala bonds which characterize the natural peptidoglycan . Therefore, the cell-free particulate preparation possesses the whole enzymatic system necessary for synthesis of cross-linked peptidoglycan. Proc Natl Acad Sci U S A, 1976 Feb, 73(2), 505 - 9 Analysis of subunit organization in chicken erythrocyte chromatin; Shaw BR et al.; Micrococcal nuclease digestion of intact chicken erythrocyte nuclei is shown to result in the formation of core nucleoprotein particles containing about 140 base pairs of DNA . These core particles, which are almost entirely devoid of histones f1 and f2c, are derived from transient nucleoprotein particles containing an average of approximately 180 base pairs of DNA . Oligomers of these latter particles may be isolated after brief nuclease digestion . The time course of digestion of these oligomers demonstrates the existence of "spacer" regions of more accessible DNA between core particles . Redigestion of purified monomer core nucleoprotein particles gives rise to both single-strand and double-strand DNA fragment patterns similar to those resulting from digestions of chromatin in situ . This observation indicates that the core particles we isolate are representative of nucleoprotein structures existing within the nucleus. Nucleic Acids Res, 1976 Feb, 3(2), 493 - 505 Tetrahymena ribosomal RNA gene chromatin is digested by micrococcal nuclease at sites which have the same regular spacing on the DNA as corresponding sites in the bulk nuclear chromatin; Piper PW et al.; Synchronised cells of Tetrahymena pyriformis GL were labelled with 3H thymidine at a stage in the cell cycle when only the mitochondrial and extrachromosomal nucleolar ribosomal DNAs were replicating . In this way it was possible to prepare nuclei labelled selectively in the DNA of the ribosomal RNA genes . Since the ribosomal RNA cistrons of these cells are also very active in serving as a template for transcription, experiments were performed to test whether these genes are organised upon a nucleoprotein subunit structure of the kind that has been found in the total chromatin of a wide range of eukaryotic cell types . Tetrahymena macronuclei were prepared labelled uniformly in their DNA with 32P and labelled only in their nucleolar ribosomal DNA with 3H . Both the ribosomal genes and the bulk chromatin were then degraded in situ using micrococcal nuclease . The DNA fragments resulting from mild digestion were analysed on gels to reveal an identical DNA degradation pattern within both the ribosomal and bulk chromatins . It is concluded that the nucleoprotein structure of nucleolar rRNA cistrons posesses a periodic repeat along the DNA which is identical to that found in the substructure of unfractionated chromatin. Mutat Res, 1976 Feb, 34(2), 175 - 86 The resistance of Micrococcus radiodurans to killing and mutation by agents which damage DNA; Sweet DM et al.; The resistance of Micrococcus radiodurans to the lethal and mutagenic action of ultraviolet (UV) light, ionising (gamma) radiation, mitomycin C (MTC), nitrous acid (NA), hydroxylamine (HA), N-methyl-N'-nitro-N-nitrosoguanidine (NG), ethylmethanesulphonate (EMS) and beta-propiolactone (betaPL) has been compared with that of Escherichia coli B/r . M . radiodurans was much more resistant than E . coli B/r to the lethal effects of UV light (by a factor of 33), gamma-radiation (55), NG (15) and NA (62), showed intermediate resistance to MTC (4) and HA (7), but was sensitive to EMS (1) and betaPL (2) . M . radiodurans was very resistant to mutagens producing damage which can be repaired by a recombination system, indicating that it possesses an extremely efficient recombination repair mechanism . Both species were equally sensitive to mutation to trimethoprim resistance by NG, but M . radiodurans was more resistant than E . coli B/R to the other mutagens tests, being non-mutable by UV light, gamma-radiation, MTC and HA, and only slightly sensitive to mutation by NA, EMS and betaPL . The resistance of M . radiodurans to mutation by UV-light, gamma-radiation and MTC is consistent with an hypothesis that recombination repair in M . radiodurans is accurate since these mutagens may depend on an "error-prone" recombination system for their mutagenic effect in E . coli B/r . However, because M . radiodurans is also resistant to mutagens such as HA and EMS, which are mutagenic in E . coli in the absence of an "error-prone" system, we propose that all the mutagens tested may have a common mode of action in E . coli B/r, but that this mutagenic pathway is missing in M . radiodurans. Biochem J, 1976 Feb 1, 153(2), 287 - 95 Studies by electron-paramagnetic-resonance spectroscopy on the mechanism of action of xanthine dehydrogenase from Veillonella alcalescens; Dalton H et al.; E.p.r- (electron-paramagnetic-resonance) spectroscopy was used to compare chemical environment and reactivity of molybdenum, flavin and iron-sulphur centres in the enzyme xanthine dehydrogenase from Veillonella alcalescens (Micrococcus lactilyticus) with those of the corresponding centres in milk xanthine oxidase . The dehydrogenase is frequently contaminated with small but variable amounts of a species resistant to oxidation and giving a new molybdenum (V) e.p.r . signal, "Resting I" . There is also a "desulpho" form of the enzyme giving a Slow Mo(V) signal, indistinguishable from that of the milk enzyme . Molybdenum of the active enzyme behaves in a manner analogous to that of the milk enzyme, giving a Rapid Mo(V) signal on partial reduction with substrates or dithionite . Detailed comparison shows that molybdenum in each enzyme must have the same ligand atoms arranged in the same manner . As with the milk enzyme, complex-formation between reduced dehydrogenase and purine substrate molecules, presumably interacting at the normal substrate-binding site, modifies the Rapid signal, confirming that such substrates interact near molybdenum . The dehydrogenase-flavin semiquinone signal is identical with that of the oxidase but, in contrast, there is only one iron-sulphur signal . The latter gives an e.p.r . spectrum similar to that of aldehyde oxidase. Biokhimiia, 1976 Feb, 41(2), 308 - 15 {Study of the structure of the histidine decarboxylase of Micrococcus sp . n . by the method of circular dichroism}; Mardashev SR et al.; Ring dichroism spectra (RD) of histidine decarboxylase (HDC) from Micrococcus sp . n . at the regions of peptide bonds (200-240 nm) and aromatic amino acids (250-300 nm) absorption are studied . The treatment of RD spectra according to methods of Greenfield-Fasman, Saksena-Vetlaufer and Mayer permits to conclude that at the pH range within 4-8 the content of ordered structures of alpha-helix type comprises 20%, that of beta-structure type-40%, while the rest 40% are represented with polypeptide chain in a disordered globular state . When pH is varied from 1 to 12, the content of alpha-helices decreases from 17 to 5% . There are two distinct dichroic bands in the spectrum of aromatic chromophores absorption (at 270 and 290 nm), the former containing tirosine, tryptophane and phenylalanine residues and the latter being induced with triptophane residues . The study of HDC RD spectra at the regions of peptide bonds and aromatic acids absorption at different temperatures has shown that a part of triptophane, tyrosine and phenylalanine residues is in an ordered structure of the alpha-helix type . The HDC undergoes irreversible changes under heating to 70 degrees and in 8 M urea . 5 M guanidine chloride eliminates the ordered HDC structure, while sodium dodecylsulphate at concentrations up to 1% does not affect the enzyme structure. Biochemistry, 1976 Jan 13, 15(1), 168 - 76 Preparation and properties of the repeating sequence polymers d(A-I-C)n-d(I-C-T)n and d(A-G-C)n-d(G-C-T)n; Ratliff RL et al.; The repeating sequence polymer d(A-I-C)n-d(I-C-T)n has been prepared using the chemically synthesized oligomers d(A-G-C)4 and d(C-T-G)4 and the DNA polymerase from Micrococcus luteus . The enzymatically synthesized polymer was used as template for preparation of d(A-G-C)n-d(G-C-T)n . Both deoxyribonucleotide polymers were characterized by nearest neighbor analyses, buoyant density measurements in cesium chloride and cesium sulfate, melting temperature, and circular dichroism (CD) spectra . The ribopolymers r(A-I-C)n-r(I-C-U)n and r(A-G-C)n-r(G-C-U)n were transcribed from d(A-I-C)n-d(I-C-T)n, and their CD spectra were compared with those of the respective deoxyribonucleotide polymers. Folia Microbiol (Praha), 1976, 21(6), 438 - 43 Thymineless death in a thymine-dependent mutant of Micrococcus radiodurans T2 in the presence of chloramphenicol and rifampicin; Rauko P et al.; A possibility to prevent cells of a thymine-dependent mutant of Micrococcus radiodurans T2 from thymineless death was investigated . It was found that the presence of chloramphenicol (CAP) in a thymineless medium only decelerated the death of cells . The presence of rifampicin (RFP) considerably decreased the death rate of cells but could not prevent thymineless death completely. Experientia, 1976, 32(7), 925 - 7 Unstable L-forms of micrococci in human foetal blood; Tedeschi GG et al.; In human foetal blood the presence of Micrococcaceae in the unstable L-form, probably taking origin from the placental transmission of minimal reproductive units, has been recognized by means of microscopic and cultural methods. Biochimie, 1976, 58(1-2), 131 - 42 Synthesis of the monomer and dimer peptide fragments of the Micrococcus lysodeikticus cell wall peptidoglycan; Mulliez M et al.; Three branched peptides, namely pentapeptide A and the two decapeptides B and C corresponding respectively to the monomer and the two dimer peptide fragments of the M . lysodeikticus cell wall peptidoglycan, were synthetized by adequate methods of peptide synthesis in homogeneous phase . The synthetized peptides showed the same electrophoretic and chromatographic behavior as the natural peptide fragments . Only decapeptide B was hydrolysed by the Myxobacter AL-1 protease by cleavage of the D-Ala-L-Ala bond and inversely, only decapeptide C was digested by the Streptomyces albus ML endopeptidase by cleavage of the D-Ala-epsilon-Lys linkage . In both enzymatic hydrolyses the pentapeptide monomer was formed. Arch Exp Veterinarmed, 1976 Jan 1, 30(1), 151 - 8 {Artificial intranasal bacterial invasion in the newborn calf . 2 . Artificial bacterial invasion using gram-positive and gram-negative strains}; Grohs G et al.; A micrococcal and a diplocaccal strain isolated from the nasal space of a clinically intact nursed calf were used for artificial bacterial invasion in the first phase of the experiment . Application of bacterial suspension prepared from those strains had no effect upon the rise of coli counts in the nasal secretion of nursed calves during their first days of age nor upon the morbidity or mortality of all 677 test animals in comparison to 665 controls . Therefore, an avirulent E.-coli strain was used in subsequent bacterial invasion experiments . The strain was retrievable up to the seventh day of age, the count having been about 10(5) bacteria per gram nasal secretion . Application of a bacterial suspension prepared from that E.-coli strain did not reduce morbidity and mortality among 820 test animals that were compared to 809 controls . Results are discussed in this paper with reference to literature. Biokhimiia, 1976, 41(7), 1203 - 7 {Mechanism of action of the specific inhibitor of respiration and phosphorylation in mitochondria--n-(N,N-di-2-chlorethyl)aminophenylacetic acid}; Iaguzhinskii LS et al.; An electrophilous inhibitor, p-(N,N-di-2-chloroethyl)amino-phenylacetic acid (I), specifically disturbs the mechanism of respiration and phosphorylation coupling in mitochondria . I inhibits respiration and ATPase activity in intact mitochondria and does not affect these processes in mitochondria and submitochondrial particles with partially or completely impaired coupling system . The data obtained show that I inhibits protonophoric function of NADH-ferricianide reductase from submitochondrial particles soluble ATPases from bovine heart and Micrococcus lysodeikticus mitochondria adsorded on octane water interface and has no effect on respective enzymes in water solutions . Cation-transferring enzymes are shown to behave with respect to the inhibitor on lipid water interface like respective enzymes in intact mitochondria, while in water solutions they behave like those in systems with the impaired coupling mechanism . Effect of I on protonophoric function of oligomycin-sensitive ATPase and bacteriorhodopsin plaques isolated from Halobacterium halobium is also studied . It is shown that the precence or the absence of I effect is due to a nature of lipid in the enzymatic complex . I is found also to inhibit specifically the transport of Ca2+ from water to octane in the presence of Ca2+-ATP-ase from rabbit sarcoplasmic reticulum. Biokhimiia, 1976 Jan, 41(1), 175 - 82 {Change in lipid-protein interactions in the membranes of bacteria exposed to gramicidin S}; Ostrovskii DN et al.; Effect of cyclopeptide antibiotic gramicidin S on some enzymes and physical state of isolated Micrococcus lysodeikticus membranes is studied . Malate and lactate dehydrogenases were monotonously inhibited under the increase of gramicidin S concentration, while the activity of NADH-dehydrogenase firstly decreased and then reversed to the initial level under further increase of gramicidin S concentration . The oxygen uptake under oxidation of NADH and malate with membranes almost completely inhibited by the antibiotic, while the activity of ascorbate-TMPD-oxidase activity slightly inhibited by the same concentration of gramicidin . The addition of Triton X-100 completely eliminated the inhibitory effect of gramicidin on malate dehydrogenase . The introduction into the membrane of spine probes (2,2,6,6-tetramethyl-4-palmitoylamidopiperidine-1-oxile and 2(14-carboxytetradecyl)-2-ethyl-4,4-dimethyl-3-oxyazolidinyloxile) revealed that gramicidin caused the condensation of membrane lipid component . It is suggested that ionic interaction of gramicidin S with membrane phospholipids brings to "a freezing" of lipids which is a direct cause of impairing the activity of membrane respiration enzymes and the change of their position in the lipid matrix, thus inhibiting energy-producing processes in cell. Biochemistry, 1975 Dec 16, 14(25), 5475 - 9 Mode of inhibition of herpes simplex virus DNA polymerase by phosphonoacetate; Mao JC et al.; Phosphonoacetate is a highly specific inhibitor of herpes simplex virus-induced DNA polymerase . Sensitivity of herpesvirus type 1 or type 2 induced DNA polymerase to the drug was similar . However, DNA polymerases from other sources such as the host cells (Wi-38), Micrococcus luteus, and hepatitis B virus were highly resistant . In addition, Escherichia coli RNA polymerase and reverse transcriptase of Rous sarcoma virus were also insensitive to the drug . Enzyme kinetic studies showed that inhibition was noncompetitive with respect to deoxyribonucleotide triphosphates . The Ki value was about 0.45 muM . The apparent Km values for dTTP, dATP, dCTP, and dGTP were 0.71, 0.75, 0.42, and 0.39 muM, respectively . The base composition of template has no profound effect on the extent of inhibition . The drug caused uncompetititve inhibition with respect to template which indicated that phosphonoacetate did not bind directly to template DNA . Results are presented which suggest that phosphonoacetate did not affect the formation of the enzyme-DNA complex but probably inhibited the elongation step of DNA polymerase reaction. Biochim Biophys Acta, 1975 Dec 16, 413(3), 394 - 414 Conformational and molecular responses to pH variation of the purified membrane adenosine triphosphatase of Micrococcus lysodeikticus; Nieto M et al.; A preparation of ATPase from the membranes of Micrococcus lysodeikticus, solubilized and more than 95% pure, showed two main bands in analytical polyacrylamide gel electrophoresis . They did not correspond to isoenzymes because one band could be converted into the other by exposure to a mildly alkaline pH value . The conversion was paralleled by changes in molecular weight, circular dichroism and catalytic properties . Denaturation by pH at 25 degrees C was followed by means of circular dichroism, ultracentrifugation and polyacrylamide gel electrophoresis . A large conformational transition took place in the acid range with midpoints at about pH = 3.6 (I = 10(-4) M), 4.3 (I = 0.03 M) and 5.3 (I = 0.1 M) . The transition was irreversible . Strong aggregation of the protein occurred in this range of pH . The final product was largely random coil, but even at pH 1.5 dissociation into individual subunits was not complete . However, partial dissociation took place at pH 5 (I = 0.028 M) . At this pH value the enzyme was inactive, but 20-30% of the activity could be recovered when the pH was returned to 7.5 . In the alkaline region the midpoint of the transition occurred near pH = 11 (I = 0.028 M) . The pK of most of the tyrosine residues of the protein was about 10.9 . The unfolding was irreversible and the protein was soon converted into peptide species with molecular weights lower than those determined for the subunits by gel electrophoresis in the presence of sodium dodecyl sulphate . Conventional proteolysis did not account for the transformation. Biochem J, 1975 Dec, 151(3), 497 - 503 Fractionation of chick oviduct chromatin . Nuclease-resistant deoxyribonucleic acid; Krall JF et al.; Chromatin isolated from several chick tissues was treated with micrococcal nuclease . A limited degree of tissue specificity of chromatin DNA resistance to nuclease digestion was observed . No difference in the extent of nuclease resistance of chromatin DNA was detected during oestrogen-induced oviduct differentiation . This suggested that the amount of non-histone chromosomal protein does not play an important role in the sensitivity of chromatin DNA to nuclease digestion . Studies of nuclease resistance of chromatin DNA after dissociation and reconstitution of chromatin proteins and ethanol extraction of chromatin indicate that the histones protect the DNA from nuclease attack . Slow thermal denaturation of nuclease-resistant DNA suggests that the protected DNA sequences may be (A+T)-rich, and the (G+C)-rich satellites present in total chick DNA are sensitive to nuclease. Biochem J, 1975 Dec, 151(3), 505 - 12 Effects of polyamines and methylglyoxal bis(guanylhydrazone) on hepatic nuclear structure and deoxyribonucleic acid template activity; Brown KB et al.; 1 . The interaction of polyamines and methylglyoxal bis(guanythydrazone) (1, 1'-{(methylethanediylidene)-dinitrilo}diguanidine) with isolated rat liver nuclei was investigated by electron microscopy . 2 . At 4mM, putrescine was without effect; however, spermidine, spermine or methylglyoxal bis(guanythydrazone) resulted in dispersed chromatin and alterations in nucleolar structure . In addition, spermidine or methylglyoxal bis(guanylhydrazone) caused marked aggregation of interchromatin granules . 3 . The DNA template property of calf thymus DNA was examined by using DNA polymerases from Escherichia coli, Micrococcus lysodeikticus and calf thymus in the presence of 0-5 mM-amine . 4 . In the presence of DNA polymerase, spermine or methylglyoxal bis(guanylhydrazone) inhibited activity, whereas putrescine or spermidine had much less effect or in some cases stimulated {3H}dTMP incorporation . 5 . Template activity which was inhibited by spermine or methylglyoxal bis(guanylhydrazone) could be partially restored by additional DNA or enzyme . 6 . When mixed with calf thymus DNA, calf thymus histone inhibited template activity as measured with E . coli DNA polymerase . The template activity of such a 'histone-nucleate' could not be restored by putrescine, spermidine, spermine or methylglyoxal bis(guanylhydrazone) . 7 . DNA template activity of isolated rat liver nuclei was tested by using E . coli DNA polymerase . None of the amines was able to increase the template activity of the nuclear DNA in vitro. J Biochem (Tokyo), 1975 Dec, 78(6), 1177 - 81 Comparative specificity of geranylgeranyl pyrophosphate synthetase of Micrococcus lysodeikticus and pumpkin; Shinka T et al.; Comparative studies on the substrate specificity of geranylgeranyl pyrophosphate synthetase from Micrococcus lysodeikticus and from pumpkin seedlin revealed that geranyl pyrophosphate was the most active of the natural substrates for the pumpkin enzyme, whereas it was the least active for the bacterial enzyme . A marked difference was also observed between the enzymes from these two sources as regards the reactivity of 3-methyl-2-alkenyl pyrophosphates as a function of the size of the alkyl group. Biochem J, 1975 Nov, 151(2), 387 - 97 A membrane-associated lipomannan in micrococci; Powell DA et al.; Membranes of Micrococcus lysodeikticus, Micrococcus flavus and Micrococcus sodonensis contain acidic lipomannans . Lipoteichoic acids could not be detected in these organisms, and the suggestion that they are substituted for by the lipomannans is strengthened by the chemical and physical resemblances between the two polymers . The mannans contain glycerol, ester-linked fatty acids and mono-esterified succinic acid residues, giving them both hydrophobic and charged properties . The M . lysodeikticus mannan has a chain of about 60 hexose units with two branch points, and is joined at its reducing end to the 1-position of a glycerol moiety bearing two fatty acid residues . Succinic acid on the mannan enables it to bind Mg2+ efficiently, and the polymer is firmly associated with the cytoplasmic membrane, probably by intercalation of its fatty acids with those of the membrane lipids. Mikrobiologiia, 1975 Nov-Dec, 44(6), 1068 - 73 {Spectrophotometric characteristics of the coccoid forms of actinomycetes}; Pridachina NN et al.; IR spectra of thw whole cells of the coccoid forms (Mycococcus and Micrococcus) isolated from lithophilous lichen were compared with IR spectra of the collection cultures of Micrococcus and Arthrobacter . Generic spectral characteristics of Mycococcus and Micrococcus are presented . Spectral heterogeneity within the genus Arthrobacter complicates the diagnosis . The cultures of the Mycococcus genus were divided into three groups according to their spectral characteristics . Spectral scans of the studied coccoid forms differ from the scans of the mycelial actinomycetes, and their intensities within the range of 900-1200 cm-1 (lipids) decrease in the series Mycococcus, Arthrobacter, Micrococcus. Biokhimiia, 1975 Nov-Dec, 40(6), 1154 - 62 Menaquinone function in the respiratory chain of Micrococcus lysodeikticus}; Lukoianova MA et al.; Menaquinone-9 which is destructed under long-wave UV-irradiation is isolated from Micrococcus lysodeikticus membranes . NAD-H, malate and lactate oxidases are observed to be inhibited under irradiation, dehydrogenases of these substrates being almost intact . Photoinactivation of menaquinone results in the reduction of only one from two cytochromes b, presented in the membrane, thus testifying the location of menaquinone-9 between cytochromes b in the respiratory chain . Reconstruction of malate, NAD-H and lactate oxidases after irradiation took place when natural menaquinone (MQ-9) or menadione (MQ-0) were added . Detailed scheme of M . lysodeikticus respiratory chain is given. Can J Microbiol, 1975 Nov, 21(11), 1676 - 80 A replica-plating method for the identification of Micrococcaceae; Bibel DJ et al.; A procedure of replica plating is described whereby all isolated colonies of Micrococcaceae can be identified with relative ease and rapidity . The method is as accurate as the recommended procedure, but permits a more complete and economical analysis of cutaneous flora in large-scale surveys . In this system, Baird-Parker carbohydrate medium was found somewhat superior to standard medium as was incubation at 35 degrees C instead of the customary 30 degrees C . Baird-Parker's broth medium for acetoin production yielded more positive results than did commercial medium, although the reactions were less distinct . However, an agar acetoin test medium was found as good or perhaps even better than Baird-Parker's medium . The classification schemes of Baird-Parker and Bergey's Manual were contrasted in the analysis of data. Nucleic Acids Res, 1975 Nov, 2(11), 2147 - 61 Physico-chemical and biological study of excision-repair of UV--irradiated phiX174 RF DNA in vitro; Heijneker HL; We have studied excision-repair of UV-irradiated phiX174 RFI DNA in vitro with UV-specific endonuclease from Micrococcus luteus (UV-endo), DNA polymerase I from Escherichia coli and DNA ligase from phage T4 infected E . coli . Excision-repair was measured a) by physico-chemical methods, i.e . by determination of the conversion of RF I DNA into RF II DNA by UV-endo and by the subsequent conversion of RF II DNA ligase, b) by biological methods i . e . by measuring the ability of the reaction product to form phages upon incubation with spheroplasts from the appropriate strains of E . coli . Using the first method, we have shown, that more than 90% of the pyrimidine dimers can be repaired in vitro; with the latter method we have shown, that the molecules which are repaired as defined by method a) have regained full biological activity . Exonuclease III was found to be not essential for excision-repair in vitro and also did not stimulate repair . From this result we conclude that UV-endo generates 3'OH endgroups, in agreement with results obtained by Hamilton et al . (1974) . The usefulness of the method presented in this paper with regard to the study of excision-repair is discussed. Biochim Biophys Acta, 1975 Oct 6, 406(2), 235 - 47 Distribution of enzymes involved in mannan synthesis in plasma membranes and mesosomal vesicles of Micrococcus lysodeikticus; Owen P et al.; The distribution of membrane-bound enzymes involved in mannan biosynthesis in plasma and mesosomal membranes of Micrococcus lysodeikticus has been investigated . Isolated mesosomal vesicles, unlike plasma membrane preparations, cannot catalyze the transfer of {14C}mannose from GDP-{14C}mannose into mannan . This appears to result from the inability of this membrane system to synthesize the carrier lipid {14C}mannosyl-1-phosphorylundecaprenol . In contrast, this is the major mannolipid synthesized from GDP-{14C}mannose by isolated plasma membranes . The possibility that substrate inaccessibility could account for the failure to detect the enzyme in isolated mesosomal vesicles appears unlikely from the lack of activity following disruption of the vesicles with ultrasound or with surface active agents . Both membrane preparations possessed the ability to catalyse the transfer of {14C}mannose from purified {14C}mannosyl-1-phosphorylundecaprenol into mannan . Furthermore, free mannan and mannan located on both unlabeled mesosomal and unlabeled plasma membranes could act as acceptors of {14C}mannosyl units from 14C-labeled carrier lipid located in prelabeled plasma membranes . The possibility that the juxtaposition of mesosomal vesicles and enveloping plasma membrane (i.e . the mesosomal sacculus) in vivo allows mannan, located on mesosomal vesicles, to accept mannosyl units from carrier lipid located in the sacculus membrane is discussed. Biochim Biophys Acta, 1975 Oct 6, 406(2), 214 - 34 Isolation and characterization of a mannan from mesosomal membrane vesicles of Micrococcus lysodeikticus; Owen P et al.; The carbohydrate content of mesosomal membranes of Micrococcus lysodeikticus has been shown to be consistently higher (about four times) than that of corresponding plasma membrane preparations . Analysis of washed membrane fractions by gas-liquid chromatography indicated that mannose was the major neutral sugar of both types of membrane (accounting for 95 and 89%, respectively, of the mesosomal and plasma membrane carbohydrate) . Small amounts of inositol, glucose and ribose were also detected . We have shown by polyacrylamide gel electrophoresis in sodium dodecylsulphate and by precipitation and agar gel diffusion experiments with concanavalin A that a mannan is the major carbohydrate component of both types of membrane . This polymer can be selectively released from mesosomal membranes by a simple procedure involving low ionic strength-shock and heating to 80 degrees C for 1 min, and purified by ultrafiltration and ethanol precipitation . The mannan contains mannose as the only neutral carbohydrate, is not phosphorylated and does not contain significant amounts of amino sugars or uronic acids . Agar gel electrophoresis experiments, however, indicate an anionic polymer whose acidic properties are eliminated upon mild base hydrolysis . Analysis of native mannan by infrared spectroscopy reveals absorption bands attributable to ester carbonyl groups and to carboxylate ions, consistent with the presence of succinyl residues in the polymer (Owen, P . and Salton, M.R.J . (1975) Biochem, Biophys . Res . Commun . 63, 875--800) . A sedimentation coefficient of 1.39 S was obtained by analytical ultracentrifugation in 1.0 M NaCl and a value of one reducing equivalent per 50 mannose residues by reduction with NaB3H4 . The polysaccharide was only slightly degraded (2%) by jack bean alpha-mannosidase and could precipitate 15 times its own weight of concanavalin A . The acidic polymers was also detected in the cell "periplasm" and was secreted from cells grown in defined media during the period of decelerating growth. J Invest Dermatol, 1975 Oct, 65(4), 379 - 81 Age-related changes in the resident bacterial flora of the human face; Leyden JJ et al.; Quantitative levels of resident aerobic and anaerobic bacteria of the face, show a characteristic age-related pattern . The density of anaerobic diptheroids and surface aerobic micrococci is higher in infancy than in early childhood . At puberty the quantity of organisms increases, with significantly higher levels achieved in late adolescence . Maximum counts are attained in early adulthood and remain constant until old age when a trend toward lower numbers occurs . These changes seem to correlate with the production of sebum. Chromosoma, 1975 Sep 26, 52(2), 189 - 205 Evidence for a subunit structure of chromatin in mouse myeloma cells; McGhee JD et al.; If micrococcal nuclease is allowed to digest chromatin as it exists inside intact nuclei isolated from mouse myeloma tissue culture cells, more than 60% of the DNA can be isolated as a homogeneous fragment on a sucrose gradient . Analytical ultracentrifugation indicates that the protected DNA is native, unnicked, and about 140 +/- 10 base pairs long . After less extensive nuclease digestion, the protected DNA migrates in gels in lengths which are integral multiples of this 140 base pair "monomer" band . A submonomer band, 105 "/- 10 base pairs long, can also be detected . Similar digestion patterns were obtained by two different nuclear isolation procedures and even when intact cells were gently lysed directly in the digestion medium . These results confirm and extend the chromatin digestion studies of previous investigators and provide support for a subunit model for eukaryotic chromatin . The single strand specific S1 nuclease did not digest intranuclear chromatin under the conditions used. Experientia, 1975 Sep 15, 31(9), 1088 - 9 L- and conventional forms of micrococci in the circulating blood of thrombocytopenic patients; Tedeschi GG et al.; The multiplication of Gram-positive Cocci originating from L-forms carried by platelets of autoimmune thrombocytopenic patients, may be attributed to the primary platelet damage enhanced following interaction with bacteria. Eur J Biochem, 1975 Sep 15, 57(2), 561 - 7 Preferential digestion of (A plus T)-rich stretches of yeast mitochondrial DNA in isolated mitochondria; Zeman LJ et al.; Yeast mitochondrial DNA labelled in vitro by incubation of isolated mitochondria with DNA precursors exhibits skewed profiles on isopycnic CsCl gradients . The skew is not due to nuclear DNA nor to single-stranded mitochondrial DNA in the product labelled in vitro . Simultaneous labelling with {3H}dTTP and {14C}dGTP in vitro indicates a gradient of base composition in the DNA labelled in vitro . Thus, selective degradation of mitochondrial DNA occurs during incubation, converting large molecules having the mean density of mitochondrial DNA into smaller molecules of higher mean density and with higher G:T ratio . Similarly skewed distributions can also be produced by incubation of mitochondrial DNA labelled in vivo with the yeast mitochondrial fraction or with micrococcal endonuclease, an enzyme known to selectively hydrolyse (A plus T)-rich regions of DNA. Can J Biochem, 1975 Sep, 53(9), 1031 - 4 Inhibition of cardiolipin synthesis by end-products and other complex lipids in membrane preparations of Micrococcus lysodeikticus; De Siervo AJ; Using membrane preparations of Micrococcus lysodeikticus, the end-products of cardiolipin synthesis, cardiolipin and glycerol, were shown to inhibit cardiolipin synthetase at several concentrations . Other phospholipids tested for inhibitory effects, phosphatidyl-ethanolamine, phosphatidylinositol, and phosphatidic acid were also shown to inhibit cardiolipin synthesis . Phosphatidic acid was considerably more inhibitory than cardiolipin, phosphatidylethanolamine was similar to cardiolipin, and phosphatidylinositol less inhibitory at the same concentrations . A non-phosphate-containing glycolipid was also inhibitory . In contrast, glycerophosphate had no effect on cardiolipin synthesis. Nucleic Acids Res, 1975 Sep, 2(9), 1551 - 8 The reaction of the Ca-Mg endonuclease with the A-sites of rat nucleoprotein; Burgoyne LA et al.; A quantitative study has been made on the action of rat nuclear Ca-Mg endonuclease on rat liver nuclei . In a standard 30 minute digest 0.5-1.5% of the DNA was rendered acid soluble, 1.5-4% of the chromatin was rendered buffer soluble, 50-60% of the potential cleavage sites were actually cleaved, and these cleavages were distributed evenly throughout the bulk of the genome . During these standard digests there was no significant loss of histones either in aggregate or relative to each other . Trypsin digestion of the nuclei to a trypsin resistant core did not lower the specificity of the Ca-Mg endonuclease cleavages or expose other sites to its action . Evidence is presented that indicates Ca-Mg endonuclease and micrococcal nuclease attack the same sites rather than different sites with the same spacing. Nucleic Acids Res, 1975 Sep, 2(9), 1525 - 38 Heterogeneity of chromatin fragments produced by micrococcal nuclease action; Rill RL et al.; Digestion of calf thymus chromatin with micrococcal nuclease produces a mixture of apparently well defined nucleoprotein fragments which have been partially resolved by sedimentation on linear (5-20%) sucrose gradients . Sedimentation patterns reveal a predominant peak at the 11S position, three slower components, which have not previously been reported, at the 3.4S, 5.3S and 8.6S positions, and three faster components at the 17S, 22S and 26S positions . DNA isolated from the 3S to 12S region of gradients has been resolved on polyacrylamide gels into nine to ten discrete components ranging from 47 to 156 base pairs in length . A nearly identical pattern of small DNA products was obtained from chromatin digested in intact nuclei . These data suggest that chromatin contains either several types of subunits or predominently a single type of subunit which can be asymmetrically cleaved at any one of four or more sites. Proc Natl Acad Sci U S A, 1975 Sep, 72(9), 3320 - 2 Electron microscopy of defined lengths of chromatin; Finch JT et al.; Defined lengths of chromatin were prepared by brief digestion with micrococcal nuclease and fractionation in a sucrose gradient . A length containing a given number of 200 base pair repeating units appeared as the same number of 100 A beads in the electron microscope . The distance between beads within a length was small, usually less than about 20 A. Biokhimiia, 1975 Sep-Oct, 40(5), 993 - 8 {Adenosine triphosphatase from the membrane of Micrococcus lysodeikticus}; Mileykovskaya EI et al.; A preparation of ATPase with a high specific activity was isolated from the membrane of M . lysodeikticus . The enzyme was studied using UV-spectroscopy and circular dichroism . The homogeneity of the protein preparation was shown by gel electrophoresis . The catalytic properties of the enzyme were studied using steady state kinetic methods . The values of Km app . and kcat were determined to be 6-10(-4) and 6 mumoles/mg/min respectively . It is shown that ADP is an effective inhibitor of the ATPase reaction, and the inhibition activity increases in the presence of an excess of Ca2+ . The nature of the rate dependence of the ATPase reaction on the concentration of the substrate and on Ca-ADP corresponds to a competitive type of inhibition with binding several molecules of Ca-ADP in the active site of the enzyme. Proc Natl Acad Sci U S A, 1975 Sep, 72(9), 3711 - 5 Antigenic and enzymatic architecture of Micrococcus lysodeikticus membranes established by crossed immunoelectrophoresis; Owen P et al.; By crossed immunoelectrophoresis with membrane antiserum, 17 antigens have been detected in fractions from plasma membranes of M . lysodeikticus solubilized with Triton X-100 . Absorption tests with protoplasts have demonstrated that eight of the antigens are expressed on the surface . Of these antigens the major one has been identified as a succinylated mannan . Five of the principal immunoprecipitates unaffected by absorption with protoplasts were shown by zymograms to possess the following enzymic activites: succinate dehydrogenase (EC 1.3.99.1), ATPase (EC 3.6.1.3), NADH dehyrogenase (EC 1.6.99.3)(two separate components), and malate dehydrogenase (EC 1.1.1.37) . These enzymes or enzyme-complexes are, therefore, not expressed on the outer surface of the protoplast membrane. Biochim Biophys Acta, 1975 Aug 21, 402(2), 142 - 9 Effect of activated nitrofurans on DNA; Tu Y et al.; Enzymically activated nitrofurazone reacts with co-valently closed circular DNA (derived from Escherichia coli minicells carrying lambdadv) to give at least two kinds of damage: breaks which are detected on neutral sucrose gradients and alkali-labile lesions in DNA which are converted to breaks when the DNA is subsequently Treated with alkali . DNA, isolated from nimicells exposed to the drug, also contains lesions which are converted to breaks upon treatment with endonuclease preparations obtained from Micrococcus luteus . Minicells repaired both breaks and nuclease-susceptible lesions within 2 h but did not repair alkali labile lesions within that time . Experiments with three other nitrofurans show that there are considerable differences in the degree to which DNA is damaged by activated metabolites of various derivatives and that the potency of the compounds as mutagens and carcinogens is correlated with the amount of damage caused to minicell DNA. Biochemistry, 1975 Aug 12, 14(16), 3604 - 11 Studies on interaction between poly(L-lysine58, L-phenylalanine42) and deoxyribonucleic acids; Santella RM et al.; A random copolymer of 58% L-lysine and 42% L-phenylalanine, poly(Lys58Phe42), was used as a model protein for studying the role of phenylalanine residues in protein-DNA interaction . Complexes between this copolypeptide and DNA, made by direct mixing, were studied by absorbance, circular dichroism (CD), fluorescence, and thermal denaturation . Complex formation results in an increase in absorbance, and an enhancement, red-shift, and broadening of phenylalanine fluorescence . The fluorescence enhancement is opposite to the quenching observed when a tyrosine copolypeptide is bound to DNA (R . M . Santella and H.J . Li (1974), Biopolymers 13, 1909) . The positive CD band of DNA near 275 nm is reduced and red-shifted by the binding of the phenylalanine copolypeptide to a greater extent than by the tyrosine copolypeptide . Thermal denaturation of the complexes in 2.5 times 10(-4) M EDTA (pH 8.0) shows three characteristic melting bands . For complexes with calf thymus DNA, free base pairs melt at Tm,I (47-49 degrees) and copolypeptide-bound base pairs show two melting bands (Tm,II at 73-75 degrees, and Tm,III at 88 -90 degrees) . Similar thermal denaturation results have been observed for complexes with Micrococcus luteus DNA . The fluorecence intensity of the complexes is greatly increased when the temperature is raised to the Tm,II region . In addition to fluorescence measurements, the effects of increasing temperature on absorption and CD spectra of the complexes were also studied . Stacking interaction between the phenylalanine chromophore and DNA bases, either partial or full intercalation, is implicated by the experimental results . Several mechanisms are proposed to describe the reaction between the copolypeptide and DNA, and thermal denaturation of the complex. Nucleic Acids Res, 1975 Aug 8, 2(8), 1391 - 400 Specificity of deoxyribonucleic acid transmethylase induced by bacteriophage T2 . I . Nucleotide sequences isolated from tmicrococcus luteus DNA methylated in vitro; van Ormondt H et al.; (Deoxyribonucleic acid from Micrococcus luteus was methylated in vitro in the presence of S-adenosyl-(14C methyl)methionine with a DNA methyltransferase purified from extracts of te . coli infected with bacteriophage T2 . The labelled DNA was degraded by enzymatic and specific chemical methods and the resulting short oligonucleotides were separated and characterized . tthe analytical data permit the conclusion that the tdna transmethylase reacts specifically with N-G-A-T-C-N sequences in which it converts adenine to a 6-methyl-aminopurine residue. J Bacteriol, 1975 Aug, 123(2), 678 - 86 Association of lack of cell wall teichuronic acid with formation of cell packets of Micrococcus lysodeikticus (luteus) mutants; Yamada M et al.; Morphological mutants of Micrococcus lysodeikticus (luteus) were isolated by treatment with N-methyl-N'-nitro-N-nitrosoguanidine . They occurred on plates in large, regular cell packets, whereas the parent cells usually grew as groups of two or four cells or as short chains . The mutants required a much higher concentration of Mg2+ for growth than the parent cells . The concentrations of Mg2+ and other components of the culture medium tested did not significantly affect the morphology of either the parent or mutant strains . The mutant strains were not agglutinated by antiserum to M . lysodeikticus, which mainly interacts with teichuronic acid on the cell surface, and chemical analysis of isolated cell walls of the mutants indicated the absence of teichuronic aicd . No significant differences were detected between the parent and mutant strains in the amounts of other cell wall components, e.g., peptidoglycan, protein, and teichoic acid . They possible roles of teichuronic acid in cell separation and attachment of divalent cations are discussed. Hoppe Seylers Z Physiol Chem, 1975 Aug, 356(8), 1297 - 304 Synthesis of a chemically reactive analog of the nonsense codon U-G-A . Its reaction with ribosomes of Escherichia coli; Pongs O et al.; Nitrophenylated 5'-uridylic acid could be employed as primer in a polyribonucleotide nucleotidyltransferase (Micrococcus luteus) reaction to yield 5'-nitrophenylated Pu-G-A . After reduction of the nitrophenyl moiety and subsequent bromoacetylation, a 5'-bromoacetamido-phenyl-phosphorylated U-G-A was obtained, which could be used as an affinity label for the ribosomal binding site of the nonsense codon . If freshly prepared active ribosomes were employed in the incubation mixtures, the U-G-A analog reacted exclusively with one protein, which is tentatively identified as protein S18 . Exposure of ribosomes to low temperatures gave rise to a reaction of the U-G-A label with another protein, which was identified as protein S4, the ram gene product . The results of the affinity labeling experiments with the chemically reactive U-G-A derivative are very similar to that obtained with a corresponding derivative of the initiation codon A-U-G (O . Pongs and E . Lanka (1975) Proc . Natl . Acad . Sci . U.S.A . 75, 1505-1509), which suggests that 70S ribosomes have one preferential codon binding site. Biokhimiia, 1975 Jul-Aug, 40(4), 775 - 82 {Effect of levomycetin (chloramphenicol) on the biosynthesis of membrane proteins, structure and some functions of Micrococcus lysodeikticus bacterial membranes}; Zhukova IG et al.; Levomycetin (chloroamphenicol), an inhibitor of protein synthesis, caused drastic changes in the molecular organization of bacterial membranes being introduced into the cultural medium of Micrococcus lysodeikiticus (50-100 mkg/ml . Isolated membranes of levomycetin-treated cells are enriched with lipids as compared with the control, they are more labile and they lose the X protein component and a considerable part of dehydrogenases, which results in the significant inhibition of all the respiration chain . At the same time the content of cytochrome alpha was increased by 17%, and the activity of malate dehydrogenase (as estimated in cell lysates) was two-fold increased in levomycetin-treated cell as compared with the control . It means that biosynthesis of some membrane proteins can be twice more resistant to the action of the antibiotic than the biosynthesis of other proteins, the total protein biosynthesis being significantly depressed (the incorporation of labelled leucine in membrane proteins is inhibited by 78%, and in cytoplasmic proteins-by 83%) . The ratio of the respiration rate of intact levomycetin-treated cells to the protein content or to the cell bulk was similar to that of the control culture, which testifies the stability of membranes in vivo even under considerable "fattening" . The loss of dehydrogenases and the X protein from the membranes apparently takes place at the moment of the cell rupture during the lysis in hypotonic medium . The ratio of the respiration rate of intact levomycetin-treated cells to the content of cytochromes a, b, c was 1.15-1.55 times as low as that of control cells which is probably due to the tendency of respiration components to the independent translocation in the membrane and is the result of the decrease in the concentration of the respiration components under the less than fattening greater than of the membrane. Eur J Biochem, 1975 Jul 1, 55(2), 369 - -3 Studies on the specificity of action of bacteriophage T4 lysozyme; Mirelman D et al.; Lysozyme from bacteriophage T4 was found to digest a soluble, uncrosslinked peptidoglycan which is secreted by cells of Micrococcus luteus when incubated in the presence of penicillin G . Analysis of the enzymatic degradation products shows that T4 acts as an endo-acetylmuramidase capable of cleaving glycosidic bonds only at muramic acid residues that are substituted with peptide side-chains . The results indicate that the secreted peptidoglycan may consist of a mixture of chains, approximately half of which are substituted by peptide side chains on most of their muramic acid residues, while the other half is made up of chains in which the muramic acid moieties are unsubstituted.
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