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)

The antibody response of rabbits to Micrococcus lysodeikticus is characterized by the production of a high concentration of antibodies which manifest markedly reduced heterogenicity. The specificity of these antibodies was studied and it revealed that M. lysodeikticus contains 2 major antigens: both the glucose-N-acetyl-aminomannuronic acid polymer obtained by formamide extraction of the cell walls and peptidoglycan solubilized by ultrasonic treatment gave precipitin reactions with hyperimmune antisera. By means of inhibition studies of the glucose-mannose polymer specificity, glucose appeared as the immunodominant sugar in the majority of antibodies studied. Inhibitions studies also confirmed that both the glycan and peptide moieties constitute antigenic determinants of M. lysodeikticus peptidoglycan. Antibodies to the glucose-mannose-polymer and the peptidoglycan were specifically fractionated by use of immunoadsorbents formed from lysozyme solubilized cell walls and activated Sepharose. Both antibody specificities showed a limited heterogeneity by isoelectric focusing. Finally, because antisera to M. lysodeikticus are a rich source of antibodies to peptidoglycan, emphasis is placed on the possible usefulness of this system for studies of clonal dominance.
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PMID:Isolation and characterization of homogenous rabbit antibodies to Micrococcus lysodeikticus with specificity to the peptidoglycan and to the glucose-N-acetylaminomannuronic acid polymer. 5 38

Peptidoglycan is responsible for the endotoxin-like properties of the streptococcus cell wall. The pyrogenic response of rabbit to group A streptococcus peptidoglycan prepared by hot formamide or TCA is dose-dependent and is increased if the material is ultrasonically solubilized. The pyrogenicity can be eliminated by the antiserum to the peptidoglycan or by the degradation of the material by lysozyme. Peptidoglycans prepared from cell walls of group B and L streptococci, Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus pneumoniae produce fever effects comparable to the response after group A streptococcus peptidoglycan. Spirillum serpens and Escherichia coli contain in addition to endotoxin the peptidoglycan which is also pyrogenic. Repeated injections of bacterial peptidoglycan to rabbit result in tolerance to the fever effect. Cross-tolerance was recorded only exceptionally. Rabbits tolerant to endotoxin respond with a lower fever to S. aureus and group A streptococcus peptidoglycans. Intravenous administration of peptidoglycan to rabbit causes extensive alterations in the heart characterized by various stages of the degenerative and necrotic process. Local Shwartzman reaction can be elicited in rabbit by peptidoglycan used either as a preparative or as a provocative dose in combination with endotoxin, or it can be used for both doses. The results obtained with peptidoglycans prepared from various bacteria are fully comparable. Non-specific resistance of mice to infection induced by streptococcus cell walls was found to be dependent on the peptidoglycan activity; cell wall proteins and polysaccharide are inactive. These properties of peptidoglycan resemble those known from endotoxin studies. The data presented suggest the role of peptidoglycan in pathological reactions resulting from host-parasite interaction.
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PMID:Endotoxin-like properties of the peptidoglycan. 12 56

The resistance of native and trypsin-treated [14C] glucose-labeled cell walls to degradation by lysozyme and human lysosomal enzymes was confirmed. In contrast, chemically N-acetylated cell walls undergo significant degradation by these enzymes in the pH range of 4.5 to 5.5 without prior removal of the group-specific carbohydrate. N-acetylation after removal of the group A carbohydrate by formamide extraction renders the cell walls considerably more susceptible to these enzymes than by formamaide extraction alone. It appears, therefore, that unless N-acetylation can occur in vivo, streptococcal cell walls are minimally degraded, if at all, by human peripheral blood leukocytes or lysozyme. Examination of leukocyte extracts from normal subjects and patients with post-streptococcal syndromes revealed no qualitative differences in ability to dissolve streptococcal cell walls.
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PMID:Degradation of 14C-labeled streptococcal cell walls by egg white lysozyme and lysosomal enzymes. 77 36

The formamide linkage of an inactive lysozyme derivative (1-NFK-lysozyme), formed by selective ozonization of tryptophan 62 in hen egg-white lysozyme [EC 3.2.1.17] was hydrolyzed with dilute acid faster in the frozen state at about --10 degrees than at 20 degrees. On hydrolysis of 1-NFK-lysozyme the low lytic activity increased to approximately 80% of that of native lysozyme. It is suggested that the binding ability associated with kynurenine 62 in the lysozyme derivative formed by this hydrolysis may be responsible for increase in enzymatic activity.
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PMID:Enrichment of enzyme activity on deformylation of 1-NFK-lysozyme. 100 77

1. The reactivity of alpha-chymotrypsin toward p-nitrophenylacetate has been studied in dimethylformamide, dimethylsulfoxide, formamide and methylacetamide. p-Nitrophenol is liberated in dimethylsulfoxide only. 2. The reactions of alpha-chymotrypsin in dimethylsulfoxide are characterized by the same kinetic and equilibrium constants with either the p-nitrophenyl esters of straight chain carboxylic acids (from acetic to n-caprylic) or with the "specific substrate", N-carbobenzoxy-DL-phenylalanine p-nitrophenyl ester. This signifies that reactions of alpha-chymotrypsin in dimethylsulfoxide, unlike those in aqueous medium, have no specificity toward su-strate structure. 3. The stoichiometry of alpha-chymotrypsin reactions in dimethylsulfoxide was shown to be about five moles of substrate per mole of enzyme. After attaining this stoichiometry, the reaction is completed. 4. Optical rotatory dispersion spectra indicate that in non-aqueous media alpha-chymotrypsin undergoes a large conformational transition which results in a random coil. 5. Chymotrypsinogen, trypsin, trysinogen, lysozyme and serum albumin react with p-nitrophenylacetate in dimethylsulfoxide at rates which are approximately equal to those of alpha-chymotrypsin. Thus, the "activity" of alpha-chymotrypsin in dimethylsulfoxide toward p-nitrophenylacetate does not differ from the "activity" of other proteins, some of which are not even hydrolytic enzymes.
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PMID:The reactions of alpha-chymotrypsin and related proteins with ester substrates in non-aqueous solvents. 120 14

Both alpha zein purified from a commericial preparation and beta zein prepared fresh from corn are soluble in the nonaqueous solvents formamide and dimethylformamide; in this regard zein resembles water soluble proteins such as insulin, ribonuclease, and lysozyme. On the basis of osmotic pressure measurements made in both formamide and dimethylformamide, alpha zein has a number average moleular weight of 21000-24000 daltons and shows no tendency to aggregate or dissociate. Beta zein exists in an aggregated state (dimer and higher forms) in dimethylformamide. Formamide dissociates the beta zein dimer into monomer units but aggregation to higher species occurs with increasing protein concentration.
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PMID:Molecular weight of an extremely hydrophobic protein, zein, in dimethylformamide and in formamide. 126 May 2

The biological activity of Odontomyces viscosus, which has been reported to cause periodontal disease in hamsters, was examined. The microorganism was cultured anaerobically in Brain Heart Infusion broth, and the cells were harvested. The washed cells were injected intradermally into the abdomen of rabbits. After 72 hr, a well-defined, firm, raised nodule (about 1.0 by 1.5 cm) with an erythematous border was seen at the injection site. Suspensions of cell wall and cytoplasmic material were injected intradermally, and the lesions appeared only at the site of cell wall injection. The cell walls, which were then treated with trypsin, pepsin, and ribonuclease, again produced the characteristic lesion. These nodular dermal lesions persisted for a minimal time of 10 days. The enzymatically treated cell walls were then hydrolyzed with 1 n HCl, and such hydrolysis up to 1 hr failed to alter the toxic activity of the cell walls. Similar dermal nodular lesions were obtained by injection of enzymatically treated cell walls of strains of Staphylococcus aureus, Streptococcus groups B, C, E, F, K, Lactobacillus casei, and Actinomyces israelii. Treatment with hot and cold trichloroacetic acid solutions and proteolytic enzymes, or with formamide, yielded insoluble fractions which produced the characteristic nodular lesions. The size of the lesion resulting from injection of these fractions was proportional to the amount of the injected material. The active fraction, which does not appear susceptible to hydrolysis by lysozyme, is thought to be cell wall mucopeptide. Histological studies showed skin abscesses due to the toxic reaction; however, in addition to the acute inflammatory reaction, there was local eosinophilia.
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PMID:Toxic properties of the cell wall of gram-positive bacteria. 533

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

The reactivity of alveolar macrophages (AM) to cells and cell wall fractions (CWF) of Micropolyspora faeni was investigated. Exposure of cultured AM to M. faeni and its CWF caused the AM to form clumps or aggregates which remained attached to the culture dish surface. Other gram-positive and gram-negative bacteria as well as yeast, zymosan, latex microspheres, and isolated peptidoglycan from Listeria monocytogenes did not cause this response. The response was independent of species source and antibody content of the serum used in culture. The use of heat-inactivated sera negated the role of complement activation in the aggregation of AM. AM cultures required a period of culture before exposure to cells or CWF for this response to occur. This response was both time and dose dependent. Rabbit peritoneal macrophages also exhibited the clumping response. Degradation of a purified CWF, fraction 3, with lysozyme greatly diminished the clumping response. Chemical purification of fraction 3 with periodate, formamide, or trichloracetic acid also decreased this activity. These data suggest that the major active component causing this response is peptidoglycan but that other materials associated with the cell wall may also be important. A soluble-factor chemotactic for normal rabbit AM was found in the culture fluid of AM exposed to fraction 3. M. faeni cells and CWF also caused normal rabbit AM to chemiluminesce.
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PMID:Effect of Micropolyspora faeni cells and cell wall fractions on rabbit alveolar macrophages. 683 24

Activation of the alternative pathway of complement is known to be initiated by bacterial structures. We have fractionated Propionibacterium acnes cells, purified various cell fractions, and tested their complement-activating ability in human serum chelated with ethyleneglycol bis-(beta-aminoethylether)-N,N1-tetraacetic acid. The majority of complement-activating activity was localized in the wall fraction. This activity was resistant to lipid extraction, protease, RNAse, DNAse and lysozyme treatment. NaIO4, formamide, and hot (but not cold) trichloroacetic acid (TCA) extraction ablated the complement-activating capacity of cell walls. Compounds removed by extraction failed to consume significant hemolytic activity against antibody-coated sheep erythrocytes (EA). Addition of TCA-extracted soluble material to cell wall suspensions resulted in an inhibition of hemolytic consumption by the cell wall. These results indicate that, in P. acnes, complement-activating molecules are located in the cell wall and are carbohydrate in nature. Peptidoglycan, lipid, protein, and nucleic acid do not appear to contribute to the cell wall's ability to activate complement.
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PMID:Activation of the alternative pathway of complement in human serum by Propionibacterium acnes (Corynebacterium parvum) cell fractions. 727 77


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