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)

A bacteriolytic enzyme, PR1-lysozyme, has been purified from the lysate of mitomycin C-induced pyocinogenic Pseudomonas aeruginosa, by acrinol treatment, Amberlite CG-50 chromatography, ammonium sulfate fractionation, Sephadex G-100 gel filtration and two cycles of SP-Sephadex C-50 chromatography. Homogeneity of the preparation was demonstrated by three electrophoretic techniques. PR1-lysozyme is a basic protein (pI, 9.4) and consists of a single polypeptide chain having a molecular weight of 24,000. The amino acid composition of the protein was analyzed, and no cystein residue was found among more than 210 amino acid residues. The optimum pH for enzymatic activity was 6.4 and the enzyme exhibited about 50 to 70 times greater specific activity than hen egg-white lysozyme when assayed with chloroform-killed P. aeruginosa as a substrate. By analyzing the products of enzymatic action on purified peptidoglycan of P. aeruginosa, the enzyme was identified as an N-acetylmuramidase, i.e., the same classification as hen-egg-white lysozyme. PR1-lysozyme did not show any activity towards intact cells of gram-positive and gram-negative bacteria tested. However, the enzyme was able to lyse chloroform-killed gram-negative and gram-positive bacteria.
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PMID:Bacteriolytic enzyme induced from pyocinogenic Pseudomonas aeruginosa. Purification and characterization of PR1-lysozyme. 2 69

Microorganisms capable of producing L-pyrrolidonecarboxylate peptidase [L-pyrrolidonyl peptidase, EC 3.4.11.8] were screened and a strain of Bacillus amyloliquefaciens was chosen as one of the most potent producers of the enzyme. The enzyme was purified from lysozyme-lysate of the bacterial cells by salting out with ammonium sulfate, adsorption on DEAE-cellulose, covalent chromatography on PCMB-Sepharose and by gel filtration on Sephadex G-150. By these procedures, the enzyme was purified about 800-fold with an activity recovery of 9%, and the preparation was electrophoretically homogenous. The enzyme was most active and stable at pH 7-8. The presence of 2-mercaptoethanol and EDTA was effective for stabilizing the enzyme. The molecular weight was estimated to be 72,000 by the gel filtration method and to be 24,000 by SDS-polyacrylamide gel electrophoresis, suggesting that the enzyme is a subunit oligomer, presumably trimer. The enzyme was inactivated by the addition of PCMB, sodium tetrathionate, Hg2+ and Cu2+, but the activity lost was restored by the addition of 2-mercaptoethanol and EDTA. The purified enzyme split amide and ester linkages in L-pyroglutamyl derivatives of L-alanine, beta-naphthylamine, alpha-naphthol, and 4-methylumbelliferone, but was completely inert towards various peptides and esters used as substrates for usual amino- and carboxy-peptidases, and for endopeptidases such as trypsin, subtilisin and alpha-chymotrypsin.
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PMID:Purification and characterization of L-pyrrolidonecarboxylate peptidase from Bacillus amyloiliquefaciens. 2 93

Mycobacterium ulcerans produces an exotoxin in culture which, when inoculated into guinea pig skin, causes inflammation, necrosis, edema, and other histopathological changes resembling those in infections of humans. The toxin was resistant to heat and to alkalies and was moderately acid labile. Toxic activity was destroyed by Pronase, phospholipase, lipase, amylase, and glucosidase but not by trypsin, collagenase, cellulase, lysozyme, hyaluronidase, or neuraminidase. Toxic activity was resistant to treatment with 2-mercaptoethanol, urea, guanidine hydrochloride, p-chloromercuribenzoate, ethylenediaminetetraacetate, and sodium deoxycholate but was destroyed by sodium m-periodate and sodium dodecyl sulfate. The toxin was precipitated by a wide range of ammonium sulfate concentrations. Extraction with chlorofrom-methanol or petroleum ether destroyed its activity. Isopycnic density gradient ultracentrifugation in KBr produced a high-density lipoprotein layer with a 24-fold increase in specific activity. The results indicate that this toxin is a high-molecular-weight phospholipoprotein-polysaccharide complex.
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PMID:Further characterization of Mycobacterium ulcerans toxin. 3 Jun 94

Treatment of cells grown to exponential phase with 4% sodium dodecyl sulfate for 3 h at 100 degrees C resulted in solubilization of all cellular components except for peptidoglycan. In most strains, cells cultured in liquid gonococcal broth at pH 7.2 yielded a peptidoglycan composed primarily of N-acetylmuramic acid N-acetylglucosamine, alanine, glutamic acid, and diaminopimelic acid in a molar ratio of 1:1:2:1:1. The peptidoglycan in these cells accounted for 1 to 2% (dry weight) of the cells. However, in cells cultured at pH 6.0, the dry weight of peptidoglycan increased to 4 to 13%. Preliminary investigations indicated that the apparent increase in weight is strain dependent and is due in part to associated protein(s). Neisseria gonorrhoeae strain CS7 had elevated amounts of protein associated with the peptidoglycan regardless of growth pH. The peptidoglycan-protein complex could not be dissociated by additional extraction with sodium dodecyl sulfate, 10 M LiCl2, or ethylenediaminetetraacetate or by 7.5% polyacrylamide gel electrophoresis. The complex could be degraded by lysozyme, trypsin, chymotrypsin, Pronase B, and Chalaropsis sp. muramidase.
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PMID:Cell envelope of Neisseria gonorrhoeae CS7: peptidoglycan protein complex. 3 3

The ultrastructural study of liver tissues from 38 patients with type B viral hepatitis consistently showed the presence of hepatitis B core antigen of 21-25 nm size in the liver cell nuclei and to a lesser extent in the cytoplasm. This finding and the demonstration of the tubular form of hepatitis B surface antigen in the proliferative degranulated endoplasmic reticulum constituted the etiologic criterion for the diagnosis of the disease. The double-shelled Dane-like particles were frequently found in association with the tubular form of the surface antigen. The core particles were found in the protoplasmic processes of hepatocytes and this correlated with the immunofluorescent microscopic findings that the antigen may be shed into circulation with the protoplasm. The core antigen was found to resist digestion by various enzymes such as protease, DNase, RNase, phospholipase C, lipase, lysozyme, diastase, neuraminidase and hyaluronidase, all of which did not destroy the immunoreactivity as demonstrated by immunoelectron and immunofluorescent microscopy. Similarly, sodium dodecyl sulfate, Tween 80 and mercaptoethanol also had no effect. The formalin-fixed paraffin-embedded liver tissue sections could be treated with protease to facilitate the immunofluorescent staining for the core antigen in tissue.
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PMID:Structural and immunoreactive characteristics of hepatitis B core antigen. 5 6

Mutants of Escherichia coli tolerant to the ghosts of T-even phages (T2, T4, and T6) have been isolated from a strain supersensitive to T6 phage. First, T6 supersensitive mutants were isolated from mutagenized E. coli W2252 by replica plating to T6 phage-overlaid agar. One of them, strain NM101, was mutagenized again, grown, and then plated with a high multiplicity of T4 and T6 ghosts. Surviving cells were checked for tolerance to ghosts and adsorption of phages. One such ghost-tolerant mutant, strain GT29, was tolerant to ghosts of both T4 and T6 phages and sensitive to T2 ghosts. This mutant was also sensitive to ethylenediaminetetraacetic acid and penicillin G and intermediately sensitive to acriflavine, sodium dodecyl sulfate, sodium deoxycholate, actinomycin D, and lysozyme. Another mutant, strain GT62, was tolerant not only to T4 and T6 ghosts but also to T2 ghosts. It was sensitive to sodium dodecyl sulfate, sodium deoxycholate, penicillin G, acridine orange, actinomycin D, phenethyl alcohol, and novobiocin and intermediately sensitive to acriflavine and lysozyme. Spontaneous revertants of strain GT62 were isolated with a frequency of 2.7 X 10(-9). It is suggested that ghosts attack host bacteria indirectly through the cell surface by a mechanism similar to the transmission hypothesis that was originally adopted by Nomura (1967) to explain the mechanism of the action of colicins, and that our ghost-tolerant mutants presumably have defects in the cell surface.
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PMID:Isolation and characterization of T-even ghost-tolerant mutants of Escherichia coli. 5 59

Stable and metabolically active protoplasts were prepared from the unicellular cyanophyte, Anacystis nidulans, by enzymatic digestion of the cell wall with 0.1% lysozyme. The yield of protoplasts from intact algal cells was approx. 50%. Incorporation of L-[U-14C]leucine into cold trichloroacetic acid-insoluble material from protoplasts preparations was linear for 1.5 h and continued for an additional 2.5 h. Incorporation of radiolabeled leucine into hot trichloroacetic acid-insoluble material from protoplast preparations demonstrated protein synthesis in protoplasts in vitro. Phycocyanin is the principal phycobiliprotein and allophycocyanin is a minor phycobiliprotein in A. nidulans cells. The light-absorbing chromophore of both of these phycobiliproteins is the linear tetrapyrrole (bile pigment), phycocyanobilin. Radiolabeled phycocyanin and allophycocyanin were isolated from protoplast preparations which had been incubated with L-[U-14]leucine or delta-amino[4-14C] levulinic acid (a precursor of phycocyanobilin). The radio-labeled phycobiliproteins were purified by ammonium sulfate fractionation and ion-exchange chromatography on brushite columns. The specific radioactivity of phycocyanin and allophycocyanin in brushite column eluates (protoplasts incubated with radiolabeled leucine) was 106 000 and 82 000 dpm/mg, respectively. The specific radioactivity of phycocyanin and allophycocyanin in brushite column eluates (protoplasts incubated with radiolabeled delta-aminolevulinic acid) was 33 000 and 38 000 dpm/mg, respectively. Phycobiliproteins from protoplasts incubated with radiolabeled leucine were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. 25% of the incorporated radioactivity in protoplast lysates and approx. 60% of the incorporated radioactivity in protoplast lysates and approx. 60% of the incorporated ratioactivity in phycocyanin and allophycocyanin (in brushite column eluates) comigrated with the subunits of these phycobiliproteins on sodium dodecyl sulfate-polyacrylamide gels. Chromic acid degradation of phycobiliproteins from protoplast preparations incubated with delta-amino[4-14C] levulinic acid yielded radiolabeled imides which were derived from the phycocyanobilin chromophore. Imides from radiolabeled phycobiliproteins isolated from protoplast preparations incubated with L-[U-14C]leucine did not contain radioactivity. These results show that both the apoprotein and tetrapyrrolic moieties of phycocyanin and allophycocyanin were synthesized in A. nidulans protoplasts in vitro.
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PMID:Phycobiliprotein synthesis in protoplasts of the unicellular cyanophyte, Anacystis nidulans. 9 57

Extensively washed, dormant spores of Bacillus subtilis were disrupted with glass beads in buffer at pH 7 in the presence of protease inhibitors. Approximately 31% of the total spore protein was soluble, and another 14% was removed from the insoluble fraction by hydrolysis with lysozyme and washing with 1 M KCl and 0.1% sodium dodecyl sulfate. The residual spore integuments comprised 55% of the total spore proteins and consisted of coats and residual membrane components. Treatment of integuments with sodium dodecyl sulfate and reducing agents at pH 10 solubilized 40% of the total spore protein. Seven low-molecular-weight polypeptide components of this solubilized fraction comprised 27% of the total spore protein. They are not normal membrane components and reassociated to form fibrillar structures resembling spore coat fragments. The residual insoluble material (15% of the total spore protein) was rich in cysteine and was probably also derived from the spore coats. A solubilized coat polypeptide of molecular weight 12,200 has been purified in good yield (4 to 5% of the total spore protein). Five amino acids account for 92% of its total amino acid residues: glycine, 19%; tyrosine, 31%; proline, 23%; arginine, 13%; and phenylalanine, 6%.
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PMID:Bacillus subtilis spore coats: complexity and purification of a unique polypeptide component. 9 27

Five murine monocyte of macrophage tumor lines adapted to culture were characterized for differentiated properties. They ingested zymosan and latex beads, bore receptors for immunoglobulin and complement, synthesized lysozyme (most of which was secreted), and produced granulocyte colony-stimulating activity, either spontaneously or inducibly. Some of the lines also mediated phagocytosis and exocytosis of red blood cells (RBC) and lysis of tumor targets, dependent on the presence of specific antitarget sera. All the lines were growth inhibited by zymosan and Mycobacterium bovis BCG, but not by latex beads. Other macrophage-activating agents, dextran sulfate and lipopolysaccharide (LPS), as well as tuberculin purified protein derivative (PPD), inhibited most of the lines. Except for Fc and C receptors, most of the above properties were not found with other types of hematopoietic tumors in culture. In attempts to activate the macrophage lines in vitro to the "angry" state, we found that preincubation with concentrations of LPS and PPD cytostatic to the cells stimulated antibody-dependent RBC lysis, but not antibody-independent or tumor cytolysis. A classification of monocyte-related tumors and normal cells is proposed based on functional activities and differential sensitivity to immunostimulating agents.
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PMID:Immunologic functions and in vitro activation of cultured macrophage tumor lines. 10 54

The location of the inducible and constitutive forms of tyrosine sulfate sulfohydrolase in Comamonas terrigena was investigated by subjecting resting cells to osmotic shock and to treatment with lysozyme in the presence of EDTA. The bulk of this enzyme present in induced cells was released by these procedures, suggesting that the induced form is cell wall associated. The constitutive form present in noninduced cells was not released under these conditions. Evidence was also presented which suggests that SO4(2-)release by intact cells during exposure to tyrosine sulfate was primarily due to the action of the inducible form of the enzyme.
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PMID:Evidence for a periplasmic location in Comamonas terrigena of the inducible tyrosine sulfate sulfohydrolase. 11 Apr 29


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