Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.17 (lysozyme)
21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Structural studies were carried out on the linkage units in the teichoic-acid--glycopeptide complexes isolated from lysozyme digests of the cell walls of Bacillus coagulans AHU 1366. On treatment with 47% hydrogen fluoride, the complexes gave a disaccharide characterized as glucosyl(beta 1----4)N-acetylglucosamine together with major fragments, galactosyl(alpha 1----2)glycerol. By means of Smith degradation and partial acid hydrolysis, the teichoic acid chain was shown to be composed of the repeating units, galactosyl(alpha 1----2)glycerol-3(1)-phosphate, which were joined by phosphodiester bonds at C-6 of the galactose residues. The mild alkaline hydrolysis of teichoic-acid-linked glycan fragments yielded teichoic acid chains and disaccharide-linked glycan fragments, from which the disaccharide, glucosyl(beta 1----4)N-acetylglucosamine, was liberated by mild acid hydrolysis, whereas the same disaccharide linked to the teichoic acid chain was obtained by direct heating of the cell walls at pH 2.5. In addition, the presence of specialized glycerol phosphate units in the linkage region was shown by the isolation of tris(glycerol phosphate)3-glucosyl(beta 1----4)N-acetylglucosamine from the products of the Smith degradation of the teichoic-acid--glycopeptide complexes. Thus, it is concluded that the poly(galactosylglycerol phosphate) chain in the cell walls of B. coagulans AHU 1366 is linked to peptidoglycan through a novel linkage unit, bis(glycerol phosphate)-3-glucosyl(beta 1----4)N-acetylglucosamine.
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PMID:Structural studies on the linkage unit between poly(galactosylglycerol phosphate) and peptidoglycan in cell walls of Bacillus coagulans. 397 75

Structural studies were carried out on the polymer chains and their linkage regions in two kinds of teichoic acids, poly(N-acetylglucosamine 1-phosphate) [poly(GlcNAc-1-P)] and glycerol teichoic acid, bound to peptidoglycan in the cell walls of Bacillus pumilus AHU 1650. The poly(GlcNAc-1-P)-glycan complex isolated from lysozyme digests of the cell walls contained mannosamine and glycerol as minor components. On the basis of proton NMR spectroscopic data and isolation of N-acetylglucosamine 4-phosphate from acid hydrolysates, the poly(GlcNAc-1-P) was shown to be a polymer in which N-acetylglucosamine 1-phosphate units are joined at C-4 of the glucosamine residues. Mild alkaline hydrolysis of the poly(GlcNAc-1-P)-glycan complex gave a mannosamine-linked glycan fragment and the acidic polymer fraction that contained glycerol residues. Mild acid treatment of the mannosamine-linked glycan fragment gave the linkage disaccharide, ManNAc(beta 1----4)GlcNAc, whereas the acidic polymer fraction was degraded by this treatment into N-acetylglucosamine 4-phosphate and a glycerol-containing fragment characterized as P-(Gro-P)7 (Gro = glycerol). On the other hand, direct mild acid hydrolysis of the complex gave a fragment characterized as P-(Gro-P)7-ManNAc(beta 1----4)GlcNAc. These results lead to a conclusion that in the cell walls the poly(GlcNAc-1-P) chain is attached to peptidoglycan through a linkage unit, (Gro-P)7-ManNAc(beta 1----4)GlcNAc. By means of similar procedures, it was shown that the other cell wall polymer, glycerol teichoic acid, is also attached to peptidoglycan through the same disaccharide, ManNAc(beta 1----4)GlcNAc.
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PMID:Structural studies on the linkage unit between poly(N-acetylglucosamine 1-phosphate) and peptidoglycan in cell walls of Bacillus pumilus AHU 1650. 399 10

The external polysaccharide is a major component of Micrococcus lysodeikticus cell wall and displays distinct composition. The complete structure of the external polysaccharide had been elucidated as a basis for investigation of the cell wall structure-function relation. However, the mode of attachment of the polysaccharide to the peptidoglycan through a phosphodiester was not clear due to limitations in structural and biosynthetic studies. The present study describes purification of a lysozyme-resistant nondialyzable high-molecular-weight fragment of cell wall and identifies the sugar, D-glucose, as the point of external polysaccharide attachment to the peptidoglycan through a phosphate diester. Kinetic studies for the acid-catalyzed release of external polysaccharide from the peptidoglycan were performed in parallel with synthetic [methyl-2-acetamido-3-O-(D-1-carboxyethyl)-2-deoxy-alpha-D- glucopyranoside-6-yl]-alpha-D-glucopyranosyl phosphate and alpha-D-glucopyranosyl phosphate and showed the presence of a phosphodiester linkage between external polysaccharide and peptidoglycan. In addition, type of phosphate residue and cross-linking between muramic acid and protein part have been determined.
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PMID:The phosphate diester linkage of the peptidoglycan polysaccharide moieties of Micrococcus lysodeikticus cell wall. 401 22

Teichoic acid-glycopeptide complexes were isolated from lysozyme digests of the cell walls of Bacillus coagulans AHU 1631, AHU 1634, and AHU 1638, and the structure of the teichoic acid moieties and their linkage regions was studied. On treatment with hydrogen fluoride, each of the complexes gave a hexosamine-containing disaccharide, which was identified to be glucosyl(beta 1----4)N-acetylglucosamine, in addition to dephosphorylated repeating units of the teichoic acids, namely, galactosyl(alpha 1----2)glycerol and either galactosyl(alpha 1----2)[glucosyl(alpha 1----1/3)]glycerol (AHU 1638) or galactosyl(alpha 1----2)[glucosyl(beta 1----1/3)]glycerol (AHU 1631 and AHU 1634). From the results of Smith degradation, methylation analysis, and partial acid hydrolysis, the teichoic acids from these strains seem to have the same backbone chains composed of galactosyl(alpha 1----2)glycerol phosphate units joined by phosphodiester bonds at C-6 of the galactose residues. The presence of the disaccharide, glucosyl(beta 1----4)N-acetylglucosamine, in the linkage regions between teichoic acids and peptidoglycan was confirmed by the isolation of a disaccharide-linked glycopeptide fragment from each complex after treatment with mild alkali and of a teichoic acid-linked saccharide from each cell wall preparation after treatment with mild acid. Thus, it is concluded that despite structural differences in the glycosidic branches, the teichoic acids in the cell walls of the three strains are linked to peptidoglycan through a common linkage saccharide, glucosyl (beta 1----4) N-acetylglucosamine.
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PMID:A common linkage saccharide unit between teichoic acids and peptidoglycan in cell walls of Bacillus coagulans. 403 Jul 16

Transamination conjugates of cytidine-3'-phosphate and polycytidylic acid (poly C) with diaminopropane, diaminohexane and diaminooctane (DAO) are formed both at 25 degrees C and 60 degrees C. The extent of reaction and formation of side products, with intermittent hydrolysis to mononucleotides in the case of aminoalkyl-poly C, is monitored by reversed-phase high-performance liquid chromatography. Both Dns-DAO-poly C and succinyl-lysozyme-DAO-poly C covalent conjugates are then prepared and similarly characterized, including separation on a size-exclusion diol high-performance liquid chromatography column. The retention of the latter on a wide-pore reversed-phase column seems to be controlled by the protein moiety.
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PMID:Neonucleoproteins. Preparation and high-performance liquid chromatographic characterization of succinyl-lysozyme-diaminooctyl-polycytidylic acid and related polycytidylic acid conjugates. 403 Sep 46

The acoustic absorption of protein solutions in the presence of phosphate and other buffering ions has been studied in the physiological pH range. Buffers containing hydroxyl residues as titratable groups cause a pronounced increase of protein sound absorption, which is attributed to relaxation processes of proton transfer reactions between buffer ions and accessible imidazole and alpha-amino groups of the protein surface. Amino group based buffers like Good's buffers do not induce additional sound absorption. Measurement of the ultrasonic absorption as a function of pH and of buffer concentration, and corresponding parameter fitting of the equation describing proton transfer relaxation processes has been used to evaluate equilibrium parameters. For the imidazole group of the amino acid histidine a pK value of 6.22 and for the imidazole group of the protein lysozyme a pK value of 5.71 have been determined. In hemoglobin the ligand-linked pK changes have been monitored by recording ultrasonic titration curves.
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PMID:Ultrasonic absorption studies of protein-buffer interactions. Determination of equilibrium parameters of titratable groups. 404 4

A method has been developed for the isolation of outer membranes from Acinetobacter sp. strain MJT/F5/199A. Washed cells were broken in a French press and, after deoxyribonuclease and ribonuclease treatment, removal of intact cells, and four washes in 20 mosmol phosphate buffer, pH 7.4, with centrifugation at 25,000 x g for 10 min, preparations of cell wall fragments from which almost all pieces of plasma membrane had been removed resulted. Treatment of the cell walls with lysozyme and further washing, in the presence of 20 mM MgCl(2), yielded preparations of outer membranes. Electron microscopy of freeze-etched preparations shows that a regular pattern of subunits is present on the outer surfaces of intact cells. After negative staining, these subunits are visible on isolated walls and outer membranes; they can be removed by brief treatment with papain. In section, the cell wall structure is that typical of gram-negative bacteria, but the subunits are not detectable on the surface of the outer membrane. The outer membrane retains the appearance of a "unit membrane" in the cell wall, isolated outer membrane, and papain-treated outer membrane fractions. Both cell walls and outer membranes contain a high percentage of protein (76 and 84%, respectively) and not more than 5% carbohydrate, of which glucose and galactose are constitutents. The outer membranes of this Acinetobacter thus differ in structure and composition from those of bacteria in the Enterobacteriaceae.
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PMID:Isolation of outer membranes with an ordered array of surface subunits from Acinetobacter. 412 37

The inactivation of Clostridium perfringens type A spores (three strains of different heat resistances) at ultrahigh temperatures was studied. Aqueous spore suspensions were heated at 85 to 135 C by the capillary tube method. When survivors were enumerated on the standard plating medium, the spores appeared to have been rapidly inactivated at temperatures above 100 C. The addition of lysozyme to the plating medium did not affect the recovery of spores surviving the early stages of heating, but lysozyme was required for maximal recovery of spores surviving extended heat treatments. The percentage of survivors requiring lysozyme for colony formation increased greatly with longer exposure times or increasing treatment temperature. Time-survivor curves indicated that each spore suspension was heterogeneous with respect to the heat resistance of spore outgrowth system or in the sensitivity of the spores to lysozyme. Recovery of survivors on the lysozyme containing medium revealed greater heat resistance for one strain than has been reported for spores of many mesophilic aerobes and anaerobes. The spores of all three strains were more resistant to heat inactivation when suspended in phosphate buffer, but a greater percentage of the survivors required lysozyme for colony formation.
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PMID:Inactivation of Clostridium perfringens type A spores at ultrahigh temperatures. 435 57

The supernatant fractions of lysates of Lactobacillus plantarum metabolize mevalonate into lipids. Adenosine triphosphate and uridine, as well as related compounds, and reduced nicotinamide adenine dinucleotide phosphate or reduced nicotinamide adenine dinucleotide stimulate this process. To obtain very active supernatant fractions, the method of lysis is modified to include polyamines during lysozyme treatment of cells and subsequent shocking with citrate buffer.
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PMID:Mevalonate metabolism in supernatant fractions of lysates of Lactobacillus plantarum. 439 96

1. Particulate enzyme preparations obtained from Bacillus stearothermophilus B65 by digestion with lysozyme were shown to catalyse teichoic acid synthesis. With CDP-glycerol as sole substrate the preparations synthesized 1,3-poly(glycerol phosphate). It was characterized by alkaline hydrolysis, by glucosylation to the alkali-stable 2-glucosyl-1,3-poly(glycerol phosphate) with excess of UDP-glucose and a Bacillus subtilis Marburg enzyme system, by degradation of this latter product with 60%HF and periodate oxidation of the resulting glucosylglycerol. The specificity of the B. subtilis system previously reported (Glaser & Burger, 1964), was confirmed in the present work. 2. Pulse-labelling experiments, followed by periodate oxidation of the product and isolation of formaldehyde from the glycerol terminus of the polymer, showed that the B. stearothermophilus enzyme system transferred glycerol phosphate units to the glycerol end of the chain. The transfer reaction was irreversible. It was not determined if these poly(glycerol phosphate) chains were synthesized de novo, but it was shown that the newly synthesized oligomers were bound to much larger molecules. 3. When the B. stearothermophilus enzyme system was supplied with both CDP-glycerol and UDP-glucose, 1-glucosyl-2,3-poly(glycerol phosphate) was synthesized in addition to the 1,3-isomer. The former polymer was characterized by acid and alkaline hydrolysis, degradation with HF and periodate oxidation of the resulting glucosylglycerol, and periodate oxidation of the intact polymer followed by mild acid hydrolysis. This latter procedure removed the glucose substituents without disrupting the poly(glycerol phosphate) chain. 4. The poly(glycerol phosphate) isomers were distinguished by glucosylation with the B. subtilis enzymes and alkaline hydrolysis, the 2,3-isomer remaining alkali-labile. The proportion of 2,3-poly(glycerol phosphate) in the product increased with increasing amounts of UDP-glucose in the incubation mixture, but the total glycerol phosphate incorporated into products remained constant. It is suggested that the synthetic pathways of the two poly(glycerol phosphate) species may share a rate-limiting step.
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PMID:Teichoic acid synthesis in Bacillus stearothermophilus. 442 46


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