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)

Streptococcus suis types 1 and 2 were subjected to digestion with lysozyme. Serologically type-specific capsular polysaccharides were isolated from the lysates by ethanol precipitation followed by Sepharose 6B chromatography. The purified type 1 polysaccharide has a Kd value of 0.074 on a Sepharose 4B column and contains galactose, glucose, N-acetyl glucosamine, N-acetyl galactosamine, and sialic acid in a molar ratio of 2.42:1.00:1.00:1.13:1.39. The type 2 polysaccharide has a Kd value of 0.185 and is composed of rhamnose, galactose, glucose, N-acetyl glucosamine, and sialic acid in a molar ratio of 1.07:3.17:1.00:0.94:1.00. A comparison is drawn between the type polysaccharides of S. suis and those of group B streptococci.
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PMID:The type-specific polysaccharides of Streptococcus suis. 36 73

The outer coat fraction (OC-Fr) of Bacillus megaterium ATCC 12872 spore was isolated as a resistant residue after alkali extraction, sonic treatment, and pronase digestion of the spore coat preparation, and its backbone structure was determined by chemical analysis to be composed of galactosamine-6-phosphate (GalN-P) polymers with polypeptides and calcium. OC-Fr was not fully solubilized after ordinary acid hydrolysis. OC-Fr was insensitive to all hexosaminidases tested, and moreover, an isolated fragment, a pentamer of GalN-P, was also resistant to lysozyme and hexosaminidases even after N-acetylation, being sensitive to them to some extent after dephosphorylation. Molecular sieving experiments revealed that the outer coat limited the entry of compounds with a molecular weight of more than 2,000. Exchange of the metal on the spore surface also influenced the heat resistance. Spores of OC-Fr-deficient mutants were less resistant but were still much more resistant than the vegetative cells. These results suggest that the outer coat protects the contents of the spore against chemical, physical and enzymatic treatments owing to the chemical structure itself, composed mainly of GalN-P polymers, and the molecular sieving effect.
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PMID:Role of outer coat in resistance of Bacillus megaterium spore. 250 41

The structure of polysaccharide prepared by lysozyme digestion from the cell wall of Propionibacterium acnes strain C7 was examined. The polysaccharide fraction was composed of glucose, galactose, mannose, galactosamine, and diaminomannuronic acid in a molar ratio of 1:1:0.3:1:2. By Smith degradation of the polysaccharide, diaminouronic acid-containing fractions were obtained, and the configuration of diaminouronic acid was identified as 2,3-diacetamido-2,3-dideoxymannuronic acid [Man(NAc)2A] by means of 1H-NMR and 13C-NMR spectroscopic analyses. The results of analyses involving methylation and partial acid hydrolysis led to the conclusion that the polysaccharide has the repeating unit----6)Gal(alpha 1----4)Man(NAc)2A(beta 1----6)Glc(alpha 1----4)Man(NAc)2A (beta 1----3)GalNAc(beta 1--. In addition, a portion of the galactose residues were substituted at C-4 by alpha 1----2 linked mannotriose.
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PMID:Structure of acidic polysaccharide from cell wall of Propionibacterium acnes strain C7. 403 Jul 44

The Streptococcus mutans group b antigen of strain FA1 has been defined as to chemical composition and immunological specificity. The antigen in cold trichloroacetic acid extracts was fractionated on diethylaminoethyl-Sephadex A-25 at pH 8.5. Two forms were isolated: a polysaccharide and a mucoprotein. The two polymers reacted as a single substance in agar gel diffusion against specific adsorbed FA1 rabbit antisera but were separated by gel immunoelectrophoresis. No reaction with any other S. mutans or streptococcal group sera occurred. Galactose composed about one-third and galactosamine about 3% of the total weight of each polymer. Rhamnose was a major component of the polysaccharide (47%) but was present only in traces in the mucoprotein. The protein content of the latter was about 40%. No significant quantities of glycerol, phosphorus, or muramic acid were present in either case. Pepsin and trypsin had no effect on the serological specificity of the mucoprotein. d-Galactose and d-galactosamine were strong inhibitors (70%) of the precipitin reaction, whereas d-glucose, d-glucosamine, and N-acetyl-d-glucosamine inhibited between 25 and 35%. The results indicate that the antigen is a major antigenic component of the cell wall and that the specificity of the antigen resides in binding sites which contain both d-galactose and d-galactosamine. Agglutination of whole cells by specific group b antiserum indicates the antibody receptor sites of the polysaccharide antigen are at the surface of the streptococcal cell. The mucoprotein, but not the polysaccharide, was released from the cell by lysozyme. Lysis did not occur. The immunological specificity and other characteristics of the antigen establishes it as the identifying antigen of S. mutans group b.
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PMID:Structure and immunological specificity of the Streptococcus mutans group b cell wall antigen. 412 3

An antigen of Streptococcus mutans has been extracted from HS6 (group "a") whole cells and repeatedly fractionated by Sephadex chromatography. The antigen is shown to be a polysaccharide and contains the S. mutans group "a" antigenic site and also a second antigenic site which is common to "a" strains and 2 of 3 group "d" strains. Immunological electrophoretic and chromatographic data indicate that the two sites exist in a single molecule. The polysaccharide has a molecular weight of 107,000 and is composed of glucose, galactose, glucosamine, and galactosamine. No significant quantities of lipid, phosphorus, glycerol, or ribitol are present. Immunological specificity of the group "a" polysaccharide site depends primarily on a d-glucose . d-glucose sequence, the "a-d" site on a terminal d-galactose. Water at 100 C and pepsin (pH 2.5) at room temperature are very effective in extracting the polysaccharide from lyophilized S. mutans cells. Trypsin and lysozyme are less effective. The antigen-antibody combining site appears to be located at the cell wall surface. A small quantity of enzyme-resistant protein (5%) is firmly linked to the antigen and is considered to be a remnant of a protein to which the polysaccharide is attached in the cell wall. The composition of the protein does not identify it as a part of the peptidoglycan. No reaction to the purified polysaccharide is obtained with antisera specific for teichoic acid glycerophosphate polymers from streptococci, staphylococci, or lactobacilli.
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PMID:Extraction, purification, and chemical and immunological properties of the Streptococcus mutans group "a" polysaccharide cell wall antigen. 419 54

1. The cell wall of Clostridium welchii (type A) contains alanine, 2,6-diaminopimelic acid, glutamic acid, glycine, glucosamine, muramic acid, galactosamine, mannosamine, ethanolamine, rhamnose, galactose and phosphorus. 2. Heating with formamide at 150 degrees resolved the wall into a formamide-soluble polysaccharide fraction and a formamide-insoluble mucopeptide fraction. 3. The formamide-soluble fraction contained two components: an electrophoretically neutral polysaccharide made up of galactose, rhamnose, galactosamine and phosphorus and an electrophoretically acidic polymer containing mannosamine, ethanolamine and phosphorus. 4. The formamide-insoluble residue has been digested by lysozyme to give soluble fragments of high molecular weight. 5. All fractions contain an unknown ethyl acetate-extractable substance that can be oxidized by sodium metaperiodate. 6. The amino acid compositions of the fragments produced by lysozyme are compatible with a mucopeptide structure which has cross bridges containing all of the constituent amino acids.
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PMID:Components of the cell wall of Clostridium welchii (type A). 596 41

A Bacteroidaceae cross-reacting antigen (BCA) was isolated from several strains belonging to species in the genera Fusobacterium and Bacteroides. We showed that each of the 28 strains examined synthesized either BCA or the O-specific lipopolysaccharide (LPS). The structural difference between the two antigens was demonstrated by passive hemagglutination. BCA coated erythrocytes spontaneously and reacted with equal intensity to all bacterial antisera of BCA+ strains, whereas LPS was species specific and also coated erythrocytes after the antigen was treated with NaOH. BCA is an acid polysaccharide as proven by immunoelectrophoresis and by its capacity to form a salt linkage with lysozyme. Chemical analysis demonstrated the presence of galactosamine, glucosamine, galactose, glucose, mannose, and N-acetyl. BCA was nontoxic and did not contain lipid A in its molecule. The small particle size of BCA determined its hapten character. When attached to acid-treated Salmonella minnesota Re cells, it acted as an immunogen. By immunizing rabbits with this hapten-bacterial cell suspension, we obtained a highly potent antiserum that agglutinated all BCA+ strains.
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PMID:Isolation and characterization of a cross-reacting antigen in strains of Bacteroidaceae. 709 55

Light microscopy and transmission electron microscopy of thin sections and metal-shadowed specimens showed that the sheath of Leptothrix discophora SP-6 (ATCC 51168) is a tube-like extracellular polymeric structure consisting of a condensed fabric of 6.5-nm-diameter fibrils underlying a more diffuse outer capsular layer. In thin sections, outer membrane bridges seen to contact the inner sheath layer suggested that the sheath fabric was attached to the outer layer of the gram-negative cell wall. The capsular polymers showed an affinity for cationic colloidal iron and polycationic ferritin, indicating that they carry a negative charge. Cell-free sheaths were isolated by treatment with a mixture of lysozyme, EDTA, and N-lauroylsarcosine (Sarkosyl) or sodium dodecyl sulfate (SDS). Both Sarkosyl- and SDS-isolated sheaths were indistinguishable in microscopic appearance. However, the Mn-oxidizing activity of Sarkosyl-isolated sheaths was more stable than that of SDS-isolated sheaths. The Sarkosyl-isolated sheaths also contained more 2-keto-3-deoxyoctanoic acid and more outer membrane protein than SDS-isolated sheaths. The oven-dried mass of detergent-isolated sheaths represented approximately 9% of the total oven-dried biomass of SP-6 cultures; the oven-dried sheaths contained 38% C, 6.9% N, 6% H, and 2.1% S and approximately 34 to 35% carbohydrate (polysaccharide), 23 to 25% protein, 8% lipid, and 4% inorganic ash. Gas-liquid chromatography showed that the polysaccharide was an approximately 1:1 mixture of uronic acids (glucuronic, galacturonic, and mannuronic acids and at least one other unidentified uronic acid) and an amino sugar (galactosamine). Neutral sugars were not detected. Amino acid analysis showed that sheath proteins were enriched in cysteine (6 mol%). The cysteine residues in the sheath proteins probably provide sulfhydryls for disulfide bonds that play an important role in maintaining the structural integrity of the sheath (D. Emerson and W.C. Ghiorse, J. Bacteriol. 175:7819-7827, 1993).
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PMID:Ultrastructure and chemical composition of the sheath of Leptothrix discophora SP-6. 750 63

An Acetobacter xylinum adapted to a medium containing N-acetylglucosamine (GlcNAc) has been used to prepare a novel polysaccharide containing residual GlcNAc in cellulose. The maximum amount of incorporation was found to be 4 mol% in cellulose, when a mixed medium containing 1.4% glucose (Glc) and 0.6% GlcNAc was used for the culture of A. xylinum. The resulting polysaccharide was lysozyme-susceptible. The aminosugar residue incorporated into bacterial cellulose was found to be only GlcNAc, even if galactosamine (GalN) and glucosamine (GlcN) were applied, whereas there was little effect by mannosamine (ManN). As the major component of the resulting polysaccharide was Glc residues, even if the only carbon source in the culture medium was GlcNAc, it was suggested that there must be several enzyme systems to convert GlcNAc into Glc in the bacteria. Several ammonium salts were also found to be effective for the incorporation of GlcNAc residues when the incubation system was converted to rotatory and aerobic incubation from static incubation. The amount of residual GlcNAc was remarkably increased by the addition of lysozyme-susceptible phosphoryl-chitin (P-chitin) and increased slightly with addition of P-chitin that was less lysozyme-susceptible. However, little effect was found on addition of highly substituted P-chitin.
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PMID:Biosynthesis of a novel polysaccharide by Acetobacter xylinum. 772 42

A sheathed bacterium, Sphaerotilus natans, was cultured with vigorous shaking in a medium containing peptone. Then the biomass was harvested and treated with lysozyme, sodium dodecyl sulfate, and protease. With treatment, 1.6 mg of sheaths was obtained from 15 mg of biomass. For the preparation of sheaths of high purity, cultivation must be in the absence of glucose with sufficient aeration to prevent poly(3-hydroxybutyrate) accumulation. Carbohydrate (54.1%), protein (12.2%), and lipid (1-3%) were detected in the sheaths by colorimetric reactions and solvent extraction. Gas-liquid chromatography showed glucose and galactosamine to be present in the molar ratio of 1:4. The most abundant amino acids in the sheath protein were glycine (49.2 mol%) and cysteine (24.6 mol%). The sheaths were resistant to agents that reduce disulfide bonds (dithiothreitol and 2-mercaptoethanol) and to protease. However, sheathes were degraded completely by hydrazine, and a heteropolysaccharide composed of glucose and galactosamine (1:4) was released. The weight-average molecular weight of the polysaccharide was estimated to be 1.2 x 10(5) by gel filtration chromatography with a low-angle laser-light scattering photometer and a rotation index detector. A ladder of 1.5-kDa peptides separable by sodium dodecyl sulfate gel electrophoresis was obtained by partial hydrolysis of sheaths, suggesting the sheath protein has repeating units of 1.5 kDa.
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PMID:Isolation and chemical composition of the sheath of Sphaerotilus natans. 969 96


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