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)

Mitomycin C induced a pyocinogenic Pseudomonas aeruginosa P15 to produce a bacteriolytic enzyme, PR1-lysozyme, together with pyocin R1. No significant accumulation of the enzyme was observed inside the induced cells. The enzyme was partially purified by acrinol treatment and Amberlie CG-50 column chromatography. The mode of action of the enzyme on the host bacterial cells as well as on Micrococcus lysodeikticus cells or peptidoglycan isolated from Salmonella typhimurium, was compared with that of hen egg-white lysozyme or phage lambda-lysozyme. It is suggested that PR1-lysozyme should be classified as a glycosidase, rather than an amidase or an endopeptidase.
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PMID:Induction of bacteriolytic enzyme from pyocinogenic Pseudomonas aeruginosa and its enzymatic properties. 11 82

A novel of Escherichia coli endopeptidase was used for a selective partial hydrolysis of the peptide bridges which interlink the glycan chains in E. coli sacculi. The loosening of the murein network revealed, in the electron microscope, a preferential orientation of the glycan chains, more or less perpendicular to the length axis of the cell. Control incubations with E. coli transglycosylase or egg-white lysozyme did not leave ordered structures behind.
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PMID:Arrangement of glycan chains in the sacculus of Escherichia coli. 36 20

A membrane-bound metallo-endopeptidase that hydrolyzes human parathyroid hormone (1-84) and reduced hen egg lysozyme between hydrophilic amino acid residues was isolated from rat kidney [Yamaguchi et al. (1991) Eur. J. Biochem. 200, 563-571]. In this study, the hydrolyses of various peptide hormones and neuropeptides by the metallo-endopeptidase were examined using an automated gas-phase protein sequencer. The purified enzyme hydrolyzed the oxidized insulin B chain and substance P most rapidly, followed by big endothelin 1, neurotensin, angiotensin 1, endothelin 1, rat alpha-atrial natriuretic peptide and bradykinin, in this order. The enzyme mainly cleaved these peptides at bonds involving a hydrophilic amino acid residue. However, it cleaved bonds between less hydrophilic amino acid pairs in several short peptides, e.g. at the His5-Leu6 bond in oxidized insulin B chain, the Ile28-Val29 bond in big endothelin-1 and the Ile5-His6 and Phe8-His9 bonds in angiotensin 1. The enzyme cleavage sites of oxidized insulin B chain and angiotensin 1 were different from the reported sites cleaved by meprin and by endopeptidase 2, respectively. Kinetic determination of bradykinin hydrolysis by the purified enzyme yielded values of Km = 18.1 microM and kcat = 0.473 s-1, giving a ratio of kcat/Km = 2.62 x 10(4) s-1.M-1. The Km value was about 20-fold lower than that reported for meprin and endopeptidase 2. These results indicate that the membrane-bound metallo-endopeptidase from rat kidney is distinguished from meprin and endopeptidase 2 in its substrate specificity and is not parathyroid hormone specific, but has potential capacities to inactivate various biologically active peptide hormones and neuropeptides in vivo.
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PMID:A membrane-bound metallo-endopeptidase from rat kidney. Characteristics of its hydrolysis of peptide hormones and neuropeptides. 137 51

To provide baseline information on the immunoarchitecture of normal bone marrow, we studied cryostat-cut, frozen, and paraffin-embedded, fixed tissue sections prepared from 21 core biopsies of normal bone marrow obtained during bone marrow harvests for transplantation. A large panel of antibodies was applied that included, for frozen tissue, Leu-6 (CD1), T11 (CD2), Leu-3a (CD4), Leu-1 (CD5), Leu-2a (CD8), J5 (CD10), My7 (CD13), Leu-11 (CD16), B4 (CD19), B1 (CD20), B2 (CD21), Tac (CD25), My9 (CD33), T200 (CD45), NKH-1 (CD56), kappa and lambda chains, beta F1, Ki-67, HLA-DR, TQ1, and keratin, and for fixed tissue, leukocyte common antigen (CD45), L26 (CD20), LN1 (CDw75), LN2 (CD74), LN3, LN4, LN5, MB1 (CD45R), MB2, MT1 (CD43), MT2 (CD45R), UCHL1 (CD45R0), BM1, Ki-1 (CD30), Leu-M1 (CD15), lysozyme, KP1 (CD68), actin, S100, neuron-specific enolase, vimentin, and keratin. On fresh-frozen sections CD19 and CD2 were the most reliable and sensitive markers for B and T cells, staining 5% and 9% of marrow cells, respectively. Immunoglobulins generally showed heavy background staining, which frequently precluded an accurate assessment. The CD4 to CD8 ratio in the bone marrow was reversed from that of peripheral blood. On fixed tissues, leukocyte common antigen was found in 14% of the marrow cells, corresponding roughly to the lymphocyte population. L26, a pan-B-cell marker, stained 3% of the marrow cells. Among the other B-cell markers, LN1 and MB2 stained a large number of cells (40% to 70%), indicating reactivity with cells of the myeloid or erythroid series in addition to lymphocytes. Among the T-cell markers, UCHL1 and MT1 stained 66% and 50% of the cells, respectively, which could be explained by their cross-reactivity with myeloid cells. Nonspecific myelomonocytic markers (Leu-M1, KP1, and lysozyme) also showed reactivity in a high percentage of cells. No particular architectural distribution patterns of B or T lymphocytes were noted in either frozen or fixed bone marrow specimens. The results of this study provide normal baseline data for the immunohistologic application of hematopoietic and lymphoid markers on frozen or fixed bone marrow biopsy specimens.
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PMID:Immunoarchitecture of normal human bone marrow: a study of frozen and fixed tissue sections. 159 93

Bacteriolytic enzymes of different bond specificities, denatured by sodium dodecyl sulphate (SDS), were electrophoresed in polyacrylamide gels containing bacterial cells, then renatured after removal of SDS by diffusion. Enzyme activity was seen in sharp transparent bands resulting from bacteriolysis in the gels, while these sections containing bacterial cells appeared cloudy. Bacteriolytic enzymes including staphylococcal endo-beta-N-acetylglucosaminidase, lysozyme (N-acetylmuramidase), and lysostaphin (endopeptidase) were detected. The major bacteriolytic enzymes of Staphylococcus spp. were identified in gels after electrophoresis of crude enzyme preparations. This demonstrates the wide applicability of this method to the study of staphylococcal bacteriolytic enzymes. However, it should be noted that the method will fail to detect activities of bacteriolytic enzymes which are irreversibly inhibited by SDS.
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PMID:Visualization of endo-beta-N-acetylglucosaminidase, lysozyme, and lysostaphin after polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. 171 2

A metallo-endopeptidase, which appears to be an integral membrane protein of rat kidney, was purified to homogeneity by a series of standard chromatographic procedures. This enzyme significantly hydrolyzed human parathyroid hormone [hPTH(1-84)] and a synthetic substrate Suc-Leu-Leu-Val-Tyr-Mec (Suc = succinyl, Mec = 4-methyl-coumarinyl-7-amide). The purified enzyme had apparent molecular masses of 250 kDa on gel filtration, and 88 kDa and 245 kDa on sodium dodecyl sulfate/polyacrylamide gel electrophoresis under reducing and non-reducing conditions, respectively. Its pH optimum for activity was 8.0-8.5 and its isoelectric point was pH 4.9. Its activity was inhibited by EDTA, EGTA and o-phenanthroline, but not by phosphoramidon. The metal-depleted enzyme was reactivated by the addition of metal ions. The enzyme was also inhibited by chymostatin and eglin C, and by thiol compounds. Of the synthetic substrates examined, the enzyme hydrolyzed only Suc-Leu-Leu-Val-Tyr-Mec, one of the synthetic substrates for alpha-chymotrypsin. It did not hydrolyze synthetic substrates with less than four amino acid residues with tyrosine in the P1 position. The enzyme hydrolyzed hPTH and reduced hen egg lysozyme but did not hydrolyze azocasein or [3H]methyl-casein. NH2-terminal amino acid sequence analyses of the degradation products of hPTH(1-84) and reduced hen egg lysozyme by the purified enzyme revealed that the enzyme preferentially cleaved these peptides at peptide bonds flanked by hydrophilic amino acid residues. Amino acid analyses showed that the main degradation products of PTH were hPTH(17-29), hPTH(30-38) and hPTH(74-84). The ability of the enzyme to hydrolyze peptide bonds flanked by hydrophilic amino acid residues and its inability to degrade azocasein distinguish it from several other kidney endopeptidases reported, such as endopeptidase 24.11 and meprin.
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PMID:A membrane-bound metallo-endopeptidase from rat kidney hydrolyzing parathyroid hormone. Purification and characterization. 188 19

Hydrolysis of Staphylococcus aureus 209 P cell wall peptidoglycan was accompanied by the liberation of 1.3 mol of C-terminal and 1.2 mol of N-terminal glycine per mole of Glu as well as of 0.5 mol of N-terminal and 0.3 mol of C-terminal alanine. Gel chromatography on Sephadex G-25, ion-exchange chromatography on QAE-Sephadex A-50 and paper electrophoresis of S. aureus peptidoglycan hydrolysates gave seven homogeneous fractions; these fractions were structurally defined. Lysoamidase hydrolyzed bonds Mur-Ala, Gly-Gly and Mur-GlcN in the peptidoglycan molecule. Hydrolysis of glycan chains was accompanied by the formation of large fragments, (GlcN-Mur)9 and (GlcN-Mur)28. The lytic effect of lysoamidase on S. aureus peptidoglycan is coupled with bacteriolytic enzymes of lysoamidase: acetmuramyl amidase, glycyl--glycine endopeptidase and acetyl--muramidase.
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PMID:[Hydrolysis of a Staphylococcus aureus cell wall peptidoglycan by 209 P lysoamidase]. 208 20

The clinical and pathological findings in a patient with monocytic aleukemic leukemia presenting initially as multiple monoblastic tumors of the skin is described. The patient was a 35-year-old Japanese woman, who had first noticed multiple, asymptomatic, reddish-brown papules on her trunk. Asymptomatic enlargements of several lymph nodes were present in the bilateral cervical and axillary areas. There was no hepatosplenomegaly, sternal tenderness, bruising, or bleeding. The skin and lymph node biopsies were originally interpreted as malignant lymphoma. The diagnosis of acute monocytic leukemia was established when bone marrow involvement was detected. Immunohistochemical observation of the skin eruptions revealed the following: Positive staining with lysozyme was noted in almost half of the infiltrating atypical cells. Most of the infiltrating cells reacted positively with antisera to Leu-M5 and some of them reacted to Leu-M1. The helper T cell antibody, Leu-3a+3b, showed weak positive staining of most infiltrating cells. However, there were no reactions with antisera to Leu-6, Leu-7, Leu-14, CALLA, OKT 6, OKT 8, OKT 16, OKB 19, OKM 14, beta F1, or delta TCS1. OKM 5-positive keratinocytes were observed in some parts of the upper epidermis, although no OKM 5 expression could be detected on any tumor cells. Cytochemistry, immunohistochemistry, and electron microscopy can aid in the diagnosis of monocytic leukemia. This case illustrates the importance of using an expanded panel of monoclonal antisera in certain hematopoietic tumors.
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PMID:Cutaneous involvement as a presenting feature of monocytic leukemia: morphological and immunohistochemical studies. 227 62

The peptidoglycan of Staphylococcus aureus contains relatively short glycan chains and is highly cross-linked via its peptide chains. The material from wild-type (strain H) and mutants H28, H4B and MR-1 was freed from the teichoic-acid-linked component and then hydrolysed by Chalaropsis muramidase to yield disaccharide-repeating units of the glycan with attached peptides either non-cross-linked (monomer) or joined to similar units by one (dimer), two (trimer) or more (oligomer) peptide cross links. The resulting fragments were separated by high-resolution HPLC so that distinguishable components as large as nonamer could be identified. Extrapolation showed that, in S. aureus H, H28 and MR-1, oligomers at least as large as eicosamer formed part of the smooth distribution of oligomer fragments, whereas in strain H4B (PBP4-) the maximum size was around dodecamer. The oligomer distribution profile was related to the polymerization theories of Flory, which allow a distinction to be made between a monomer addition model, whereby each oligomer can only be synthesized by the addition of a single monomer unit to its next lower homologue, and a random addition model, in which an oligomer can be formed by linkage of any combination of its constituent smaller units. In S. aureus close approximation to the random addition model for oligomer synthesis and hence for peptidoglycan cross-linking was observed, both in PBP4+ and PBP4- mutants. The implications for secondary cross-linking in S. aureus cell wall formation are inescapable, although the possibility of an endopeptidase/transpeptidase providing later modification of the peptidoglycan is not completely ruled out.
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PMID:Peptidoglycan cross-linking in Staphylococcus aureus. An apparent random polymerisation process. 238 86

1. The effects of substance P (SP) and neurokinin A (NKA) were examined on tracheal smooth muscle tone, mucus volume output, lysozyme output and albumin transport across the ferret in vitro whole trachea in the presence and absence of the enkephalinase inhibitor, thiorphan. 2. SP (0.001-3 microM) and NKA (0.01-10 microM) contracted the tracheal smooth muscle and increased mucus volume, lysozyme and albumin outputs into the tracheal lumen. The EC50 values for SP and NKA for all of the variables measured were significantly reduced, and all of the maximum responses were significantly enhanced by thiorphan (10 microM). 3. In the presence of thiorphan, SP (1 microM) and NKA (10 microM) produced albumin concentrations in the secreted mucus (8.9 and 7.2 micrograms microliters-1) which were greater than those in the submucosal buffer (4.2 micrograms microliters-1). 4. In the presence of thiorphan, NKA was approximately 5 times more potent than SP at contracting the tracheal smooth muscle. Conversely SP was 23, 15 and 22 times more potent than NKA at stimulating mucus volume, lysozyme and albumin outputs respectively. 5. Thus, there is neutral endopeptidase in the ferret trachea in vitro which cleaves exogenously applied SP and NKA, thereby reducing the magnitude and potency of their actions. SP and NKA contract the ferret tracheal muscle probably by an action at NK2 (or NK3)-receptors but stimulate mucus volume output, lysozyme output and albumin transport across the tracheal wall probably by an action on NK1 receptors.
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PMID:Receptors mediating the effects of substance P and neurokinin A on mucus secretion and smooth muscle tone of the ferret trachea: potentiation by an enkephalinase inhibitor. 248 1


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