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PubMedDate not supplied

[Growth of Micrococcus lysodeikticus bacteria on a deuterated medium].

The object of this work was to prepare deuterated growth media and to adapt Micrococcus lysodeikticus to a medium containing deuterated-substituted organic substances and deuterium oxide instead of water. M. lysodeikticus was grown on a medium prepared from the "deuterated-cells" of Chlorella, and was capable of absorbing selectively protons from such a medium containing high concentrations of deuterium. Its deuterated cells ("monsters") produced structures consisting of several (up to 8) smaller cells, angular in shape and having a thicker (2--3 times) cell wall. Apparently, adaptation to a deuterated medium is accompanied with changes in the cell wall biosynthesis as a result of which the separation of daughter cells is interfered with in the course of cell division, and the cells are more resistant to the action of lysozyme.

Adaptation, Physiological↗
PubMed1982

Characterization of polynucleotide phosphorylase from Micrococcus luteus and isolation of the 13,000 base poly(A) product of the polymerization reaction.

A new purification procedure for polynucleotide phosphorylase from freeze-dried Micrococcus luteus cells gives approximately 20% yield of nearly homogeneous, primer-independent enzyme which is free of nucleic acid. The physicochemical properties of M. luteus polynucleotide phosphorylase are similar to those previously described for the enzyme from Escherichia coli in terms of Mr, subunit structure, and amino acid composition. The purified enzyme appears to be a trimer composed of three identical subunits (Mr 92,000), but it probably does not exist as such in the cell. Ferguson plot analyses of enzyme in cell extracts indicate that prior to purification the enzyme exists in oligomeric forms characterized by both higher charge and greater Mr. Changes in size and charge of oligomers which occur during purification are probably due to the dissociation of proteins and/or nucleic acids. Dissociation of the oligomers is achieved by dilution and electrophoresis, but reassociation does not occur after concentration. The poly(A) product of the initial polymerization stages migrates as a single band on both nondenaturing and urea-agarose gels. It is 13,000 +/- 2,000 nucleotides long, as measured by electron microscopy, and 8,000 nucleotides long by gel electrophoretic analysis. This poly(A) product remains bound to the enzyme after synthesis, yet can be easily obtained free of protein by proteinase K digestion.

Amino Acid Sequence↗
PubMed1982

Uracil-DNA glycosylase. Purification and properties of uracil-DNA glycosylase from Micrococcus luteus.

A uracil-DNA-glycosylase from Micrococcus luteus has been purified more than 3,000-fold. The enzyme preparation appears homogeneous, according to the results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It is devoid of nonspecific endonucleases, specific endonucleases for apurinic and apyrimidinic sites, 3-methyladenine or 7-methylguanine-DNA-glycosylases. It behaves as a monomer protein of 19,400 daltons. It has an isoelectric point of 7.0 +/- 0.1. It has an optimal activity between pH 5.0 and 7.0. It has no cofactor requirement and is not inhibited by EDTA. Uracil-DNA-glycosylase is highly specific for DNA containing dUMP residues, releasing uracil as product of the reaction. It is 2-fold more active on single-stranded DNA than on double-stranded DNA. If it releases uracil dimers from ultraviolet-irradiated PBS1 DNA, it is at the threshold of the detection. The apparent Km is 7 X 10(-8) M, and uracil acts as a noncompetitive inhibitor with a Ki of 3.2 X 10(-4) M. Cis-syn cyclogbutadiuracil also is a potent inhibitor, while some analogs, produced by x-irradiation of uracil and thymine, are weak inhibitors. Spermine, between 10 and 400 microM, increases the enzymatic activity by 50% and is not inhibitory at other concentrations. Spermidine activates the enzyme at concentrations of 40 to 120 microM, but becomes inhibitory at 200 and 400 microM. A new finding is that drugs which intercalate in DNA, such as ethidium bromide and ellipticine, cause a 2- to 2.5-fold activation of this enzyme activity. The concentrations giving maximal activation depend on the drug. The enzyme does not behave as a processive enzyme during uracil excision.

DNA↗
PubMedDate not supplied

[Comparative study of the action of different antibiotics on the membrane dehydrogenase activity in Micrococcus lysodeikticus].

The object of this work was to study the effect of antibiotics belonging to the groups of penicillin, tetracycline and aminoglycosides on the activity of lactate dehydrogenase, alcohol dehydrogenase and malate dehydrogenase in the membranes of Micrococcus lysodeikticus. Streptomycin, benzylpenicillin, carbenicillin and phenoxymethylpenicillin decreased the activity of the above dehydrogenases. Tetracycline and oxytetracycline activated lactate dehydrogenase and alcohol dehydrogenase in the membranes, but decreased their activity in the supernatant fraction of disintegrated membranes. The enzyme activity in the membranes was particularly inhibited by neomycin.

Anti-Bacterial Agents↗
PubMed1982

Enzymatic repair of pyrimidine dimer-containing DNA. A 5' dimer DNA glycosylase: 3'-apyrimidinic endonuclease mechanism from Micrococcus luteus.

A pyrimidine dimer-DNA glycosylase has been purified 20,000-fold from Micrococcus luteus. The enzyme is a single polypeptide chain with Mr = 18,000 that acts specifically on pyrimidine dimers, preferring those in double-stranded DNA to those in single-stranded DNA. The glycosylase cleaves the 5' residue of a pyrimidine dimer generating an apyrimidinic site and a mixed pyrimidine/pyrimidine nucleotide dimer. Under conditions of substrate excess, dimers containing a 5'-thymine are preferred to those with a 5'-cytosine residue. The glycosylase has an associated apyrimidinic/apurinic (AP) endonuclease that prefers apyrimidinic sites at the site of glycosylase action to either apurinic or apyrimidinic residues. This endonuclease is a Class I AP endonuclease in that it cleaves 3' to the AP site generating a 3'-deoxyribose moiety and a 5'-phosphate.

DNA Glycosylases↗
PubMed1982

[Optimization of lysozyme determination: comparative study of preparations of test cultures of Micrococcus luteus (M. lysodeikticus Fleming)].

About 6000 single measurements of the susceptibility of different preparations of Micrococcus luteus (M. lysodeikticus Fleming) cells were performed in order to assess their suitability for the determination of various muramidase concentrations. In particular, a turbidimetric method was compared with an agar-diffusion technique under varying experimental conditions. From our results it can be concluded that M. luteus cells washed with ether and acetone or living lyophilized cells are most suitable for turbidimetric determinations of lysozyme activity. The optimum conditions for turbidimetric assays comprised an initial transmission of 20% and a test time of 5 min. For the agar-diffusion technique fresh living or living lyophilized cells were most suitable. For a given incubation time of 3 h an incubation temperature of 50 degrees C yielded the best results.

Acetone↗
PubMed1982

Hexaprenyl pyrophosphate synthetase from Micrococcus luteus B-P 26. Separation of two essential components.

Hexaprenyl pyrophosphate synthetase was detected in extracts of Micrococcus luteus B-P 26. During the course of purification the enzyme was resolved into two components, each of which had no catalytic activity but restored the hexaprenyl pyrophosphate synthetase activity when combined with each other. Both fractions, designated components A and B in the order of their elution from hydroxyapatite, were purified free of farnesyl pyrophosphate synthetase co-occurring in the same bacterium. They appeared to be proteins of molecular weights of approximately 20,000 (component A) and 60,000 (component B). Component A was more stable as compared with component B which was easily destroyed by relatively mild heat treatment. The hexaprenyl pyrophosphate synthetase reconstituted of these two components catalyzed the synthesis of all-trans-hexaprenyl pyrophosphate from isopentenyl pyrophosphate and all-trans-farnesyl or all-trans-geranylgeranyl pyrophosphate, but it did not catalyze a reaction between isopentenyl pyrophosphate and either dimethylallyl or geranyl pyrophosphate.

Alkyl and Aryl Transferases↗
PubMed1981

[Tryptic peptides of maleylated alpha-chain of histidine decarboxylase from Micrococcus sp. n].

The maleylated alpha-chain of histidine decarboxylase from Micrococcus sp. n., containing 10 arginine residues was hydrolyzed by trypsin, and 9 peptides were isolated from the tryptic hydrolysate. A comparative study of the amino acid sequence in the tryptic peptides of alpha- and beta-chains of histidine decarboxylase allowed to establish the intramolecular homology in the alpha-chain primary structure and homology between the alpha- and beta-chains.

Amino Acid Sequence↗
PubMed1978

Effect of group specific reagents on the Mg2 +/- dependent activity of purified Micrococcus lysodeikticus ATPase.

A series of group specific reagents has been examined for their ability to inactivate Micrococcus lysodeikticus adenosine triphosphatase assayed with Mg2+ as activating divalent cation. The enzyme activity was not inhibited by sulphydryl, carboxyl, histidine, arginine and methionine specific reagents at inhibitor concentrations below 2 mM. However, the ATPase was inactivated by its chemical reaction with either one molecule of trinitrobenzenesulfonic acid or tetranitromethane, or two to four molecules of N-bromosuccinimide. These results suggest that at least one amino group, one tyrosine and two to four tryptophans are involved in the Mg2+-dependent binding or hydrolysis of ATP.

Adenosine Triphosphate↗
PubMedDate not supplied

[Effect of histidine analogs and histidyl-containing dipeptides on the decarboxylase activity of Micrococcus sp. n. histidine decarboxylase].

L-Histidinol and L-histidine hydroxamate were shown to inhibit competitively histidine decarboxylase from Micrococcus sp. n responsible for histamine biosynthesis. Constants of their inhibitory effect were found. Histidyl-containing dipeptides did not exhibit the pronounced inhibitory effect. The rate of inhibition was increased after esterification of histidyl dipeptide. Kinetics of the histidine decarboxylase inhibition by L-histidyl-L-leucine methyl ester was studied.

Carboxy-Lyases↗
PubMed1980

Aminoacylase from Micrococcus agilis.

Intracellular aminoacylase from Micrococcus agilis CCM 2131 was purified 430-fold with a 23% yield. The purified enzyme was homogeneous on polyacrylamide-gel electrophoresis and it smolecular weight was 58000. The enzyme hydrolysed stereospecifically a number of acylated L-amino acids. Its activity towards N-acetyl-L-phenylglycine was strongly inhibited by 1,10-phenanthroline, N-bromosuccinimide and mercaptoethanol, and was inhibited competitively by glycylglycine.

Amidohydrolases↗
PubMedDate not supplied

[Deuterated membranes of Micrococcus lysodeikticus: production and several biochemical properties].

A technique has been elaborated for preparation of deuterated membranes from deuterated cells of Micrococcus lysodeikticus containing 85--90% of deuterium according to the data of IR and PMR spectroscopy. Normal lysis of the deuterated cells of M. lysodeikticus requires a concentration of lysozyme which is eight times higher than for usual cells (8 mg per 1 g of wet deuterated cells) and an addition of the lytic enzymes E-2 (2 mg per 1 g of wet deuterated cells). Preparations of deuterated membranes purified from ribosomes and proteins can be obtained by treating of the lysate with RNAase and washing in 0.5 M NaCl. The purity of the deuterated membranes was evaluated by the evidence of electron microscopy, IR spectra and enzyme activities. After hydrogen atoms were substituted by deuterium, the secondary structure of the total membrane protein, the ratio between the activities of the respiratory chain enzymes, and the relative content of the lipid and protein components of the deuterated membranes remain at the same level as in the protonated ones.

Catalysis↗
PubMed1993

Insect defensin, an inducible antibacterial peptide, forms voltage-dependent channels in Micrococcus luteus.

Insect defensins are cationic, cysteine-rich peptides (approximately 4 kDa) that appear after bacterial challenge or injury in the hemolymph of insects belonging to a large variety of orders. These peptides possess anti-Gram-positive activity and participate in the potent antibacterial defense reactions of insects. Using recombinant insect defensin and the strain Micrococcus luteus as a test organism, we have investigated the mode of action of this peptide. We show that defensin disrupts the permeability barrier of the cytoplasmic membrane of M. luteus, resulting in a loss of cytoplasmic potassium, a partial depolarization of the inner membrane, a decrease in cytoplasmic ATP, and an inhibition of respiration. Potassium loss is inhibited below the order-disorder transition of the lipid hydrocarbon chains. It is also inhibited by divalent cations and by a decrease in the membrane potential below a threshold of 110 mV. We propose that these permeability changes reflect the formation of channels in the cytoplasmic membrane by defensin oligomers. This proposal is supported by patch-clamp experiments that show that insect defensins form channels in giant liposomes.

Adenosine Triphosphate↗
PubMed1976

[Comparative study of membranes of Streptococcus faecalis and Micrococcus lysodeikticus].

A comparative study of ultrastructure and IR-spectroscopy of osmotic shock membranes from cells of glycolyzing (Streptococcus faecalis) and respiring (Micrococcus lysodeikticus) bacteria, was made. The S. faecalis and M. lysodeikticus membranes differ in their cross-section. Treatment of the preliminary washed membranes of S. faecalis and M. lysodeikticus with a low ionic strength solution removes 40% and 70% of their proteins respectively, decreases the membrane cross-section but does not change their fracture faces. Pre-cooling of the membrane suspensions within the temperature range of +5 degrees-10 degrees results in the appearance of large smooth areas on S. faecalis membrane fracture faces, but does not affect the ones of M. lysodeikticus membrane. Treatment of the washed suspensions with Triton X-100 results in the appearance of drastic changes of S. faecalis membrane fracture faces and does not change the fracture faces of M. lysodeikticus membranes; treatment by the detergent does not alter the IR-spectroscopy of membranes of both bacteria. Treatment of S. faecalis and M. lysodeikticus membranes with high temperature irreversibly changes the structure of 20% and 40% of protein components respectively,, but does not affect the distribution of the subparticles on their fracture faces. It is assumed that the differences found are determined by the composition of lipid components of the membranes studied and that the amount of proteins closely bound with lipids in the membranes of S. faecalis is likely to be greater than that of M. lysodeikticus membranes.

Bacterial Proteins↗
PubMedDate not supplied

[Evolution of the immune response against Micrococcus lysodeikticus].

The immune response of rabbits immunized with Micrococcus lysodeikticus freeze-dried bacteria was studied by following the variation of the affinity and the heterogeneity of the antibodies during immunization. Partial or complete amino acid sequences were determined on the isolated light and heavy chains, and comparative studies were initiated in litter mates. No relationship between the affinity and the restriction in heterogeneity was observed. Sequences are indistinguishable from those reported for antibodies of other specificities.

Animals↗
PubMed1977

Initial reactions in biosynthesis of teichuronic acid of Micrococcus lysodeikticus cell walls.

The in vitro biosynthesis of teichuronic acid, the cell wall polysaccharide of Micrococcus lysodeikticus, occurs in two stages. In the initial stage, the particulate enzyme fraction utilizes uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) and uridine diphosphate N-acetylmannosaminuronic acid (UDP-ManNAcUA) to form three intermediates. N-Acetylglucosamine is transferred from UDP-GlcNAc to a carrier lipid present in the particulate enzyme fraction to form the first intermediate, GlcNAc carrier lipid. N-Acetylmannosaminuronic acid is then transferred from UDP-ManNAcUA to the GlcNAc carrier lipid to form ManNAcUA-GlcNAc carrier lipid, the second intermediate. Finally, the transfer of an additional N-acetylmannosaminuronic acid residue from UDP-ManNAcUA yields the third intermediate, (ManNAcUA)2-GlcNAc carrier lipid. Reactions involving UDP-ManNAcUA release uridine diphosphate. Concomitant synthesis of peptidoglycan or membrane mannan inhibits the synthesis of the teichuronic acid intermediates, thereby providing indirect evidence that the carrier lipid is undecaprenol monophosphate.

Cell Wall↗
PubMed1977

The mode of hydrolysis of a glycan portion of Micrococcus lysodeikticus cell walls by endo-N-acetylglucosaminidase or endo-N-acetylmuramidase isolated from crude barley beta-amylase.

Micrococcus lysodeikticus cell walls were digested with a pI 6.8 endo-N-acetylglucosaminidase or a pI 9.5 endo-N-acetylmuramidase. The digests were further treated with a N-acetylmuramyl-L-alanine amidase of Flavobacterium L-11 enzyme to remove the peptide portion. The products were fractionated by gel filtration and ion-exchange chromatography, and the glycan portion of fractions were analyzed for their average amino sugar chain lengths. The following results were obtained. 1. The glycan portion of the main products in the pI 6.8 enzyme digest consisted of (-N-acetylmuramic acid-N-acetyl-glucosamine-)2-3. 2. The glycan moiety of the pI 9.5 enzyme digest was mainly composed of (-N-acetylglucosamine-N-acetylmuramic acid-)3-4. 3. The glycosidic linkages around the muramic acid 6-phosphate residues which linked to a special structure through a phosphodiester bond were rather refractory to the glycosidase action of both pI 6.8 and 9.5 enzymes.

Acetylglucosaminidase↗
PubMed1977

[Isolation and properties of Micrococcus luteus endonucleas acting in DNA depurinization but inactive with pyrimidine dimers].

An endonuclease (AP-endonuclease II) that specifically attacks double stranded or single stranded depurinated DNA, resulting in single-strand nicks, has been purified 320-fold from Micrococcus luteus. The enzyme is not stimulated by 0.002 M MgCl2, it induces 3'OH-5'PO4 breaks on the 5' side of apurinic sites, it has no activity towards UV-irradiated DNA and has a molecular weight of about 30 000. In cooperation with DNA-polymerase from M. luteus and T4 DNA ligase, AP-endonuclease II has been shown capable of carrying out complete excision repair of depurinated DNA in vitro.

Coliphages↗