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 two diastereomeric tripeptides f-(S)-HmMet-Leu-Phe-OMe and f-(R)-HmMet-Leu-Phe-OMe, analogues of the prototypical chemoattractant f-Met-Leu-Phe-OH, were synthesized in solution by classical methods and fully characterized. A conformational study was performed in solution by 1H-NMR. Concomitantly, the two peptides were tested for their ability to induce chemotaxis, superoxide anion production and lysozyme secretion from human neutrophils. The conformational and biological data are discussed with regard to the proposed model of the chemotactic receptor on neutrophils.
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PMID:Synthetic formyl tripeptide chemoattractants: a C(alpha,alpha)-dialkylated, amphiphilic glycyl residue at position 1. 1284 81

The new disulphur-bridged peptide, for-Met-Leu-Cys(OMe)-Cys(OMe)-Leu-Met-for, has been synthesized and its biological properties resulting from its binding to the formyl-peptide receptor of human neutrophils characterized. Three activities resulting from this interaction were measured: directed cell migration (i.e., chemotaxis); superoxide anion production; and lysozyme enzyme release. The properties were compared with those observed for the prototypical peptide, for-Met-Leu-Phe-OMe. Chemotaxis is strongly triggered while both superoxide anion production and lysosomal enzyme release are elicited only at high concentrations and never reach the response peak observed for the prototype peptide at physiologically relevant concentrations. The derivative appears to bind with a good affinity to the formyl-peptide receptors. These results provide new information regarding the structure-activity relationship of the formyl-peptide receptor.
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PMID:Properties of a novel chemotactic esapeptide, an analogue of the prototypical N-formylmethionyl peptide. 1287 81

New synthetic analogues of the chemotactic N-formyltripeptide HCO-Met-Leu-Phe-OMe have been synthesized. The reported new models, namely Boc-Met-beta-Ala-Phe-OMe (1), HCO-Met-beta-Ala-Phe-OMe (2), Boc-Met-Tau-Phe-OMe (3), HCO-Met-Tau-Phe-OMe (4) and HCl.Met-Tau-Phe-OMe (5), are characterized by the presence at the central position of a residue of beta-alanine or 2-aminoethanesulfonic acid (taurine) replacing the native L-leucine. Whereas tripeptides 1 and 2 have been found quite inactive as chemoattractants, all the three models containing the Tau residue exhibit a remarkable activity. Superoxide anion production and lysozyme release have been also evaluated and the biological results are discussed together with the conformational preferences of the examined models.
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PMID:Synthesis and activity of HCO-Met-Leu-Phe-OMe analogues containing beta-alanine or taurine at the central position. 1457 63

Three novel phloroglucinol derivatives, garcinielliptones F (1), H (3), and I (4), and two novel terpenoids, garcinielliptones G (2) and J (5), with a new skeleton have been isolated from the seeds of Garcinia subelliptica. Their structures, including relative configurations, were elucidated by spectroscopic methods and computer-generated molecular modeling. Compound 1 showed potent inhibitory effects on the release of beta-glucuronidase and lysozyme from rat neutrophils that had been stimulated with formyl-Met-Leu-Phe (fMLP)/cytochalasin B (CB). This effect was concentration-dependent with IC(50) values of 26.9+/-2.6 and 20.0+/-1.3 microM, respectively. Compound 1 also showed a potent concentration-dependent inhibitory effect on superoxide anion generation in rat neutrophils stimulated with fMLP/CB, with an IC(50) value of 17.0+/-0.9 microM. Compound 4 showed a potent inhibitory effect on NO production in culture media of N9 cells in response to lipopolysaccharide (LPS)/interferon-gamma (IFN-gamma) in a concentration-dependent manner with an IC(50) value of 7.4+/-0.2 microM.
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PMID:Terpenoids with a new skeleton and novel triterpenoids with anti-inflammatory effects from Garcinia subelliptica. 1463 35

The conformation of several Met-Ile-Phe-Leu analogues was analyzed using circular dichroism and infra-red absorption. Their effect on human neutrophils was verified by receptor binding assays and measurements of lysozyme release. The results demonstrate that in amphipatic environments the compounds examined can be highly and weakly ordered in beta-turn structures, in dependence on their N-terminal substituents. The ability of the compounds to evoke neutrophil functions appears strongly and weakly influenced by N- and C-terminal modification, respectively.
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PMID:Conformational aspects of human formyl-peptide receptor agonists. 1467 76

G-type lysozyme is a hydrolytic enzyme sharing a similar tertiary structure with plant chitinase. To discover the relation of function and structure, we analyzed the primary structure of new G-type lysozyme. The complete 185 amino acid residues of lysozyme from rhea egg white were sequenced using the peptides hydrolyzed by trypsin, V8 protease, and cyanogen bromide. Rhea lysozyme had sequence similarity to ostrich, cassowary, goose, and black swan, with 93%, 90%, 83%, and 82%, respectively. The six substituted positions were newly found at positions 3 (Asn), 9 (Ser), 43 (Arg), 114 (Ile), 127 (Met), and 129 (Arg) when compared with ostrich, cassowary, goose, and black swan lysozymes. The amino acid substitutions of rhea lysozyme at subsite B were the same as ostrich and cassowary lysozymes (Ser122 and Met123). This study was also constructed in a phylogenetic tree of G-type lysozyme that can be classified into at least three groups of this enzyme, namely, group 1; rhea, ostrich, and cassowary, group 2; goose, black swan, and chicken, and group 3; Japanese flounder. The amino acid sequences in assembled three alpha-helices found in this enzyme group (Thammasirirak, S., Torikata, T., Takami, K., Murata, K., and Araki, T., Biosci. Biotechnol. Biochem., 66, 147-156 (2002)) were also highly conserved, so that they were considered to be important for the formation of the hydrophobic core structure of the catalytic site and for maintaining a similar three-dimensional structure in this enzyme group.
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PMID:The primary structure of a novel goose-type lysozyme from rhea egg white. 1474 79

This work was aimed at the isolation, purification, and characterization of novel antimicrobial peptides from chicken egg white lysozyme hydrolysate, obtained by peptic digestion and subsequent tryptic digestion. The hydrolysate was composed of over 20 small peptides of less than 1000 Da, and had no enzymatic activity. The water-soluble peptide mixture showed bacteriostatic activity against Gram-positive bacteria (Staphylococcus aureus 23-394) and Gram-negative bacteria (Escherichia coli K-12). Two bacteriostatic peptides were purified and sequenced. One peptide, with the sequence Ile-Val-Ser-Asp-Gly-Asp-Gly-Met-Asn-Ala-Trp, inhibited Gram-negative bacteria E. coli K-12 and corresponded to amino acid residues 98-108, which are located in the middle part of the helix-loop-helix. Another novel antimicrobial peptide inhibited S. aureus 23-394 and was determined to have the sequence His-Gly-Leu-Asp-Asn-Tyr-Arg, corresponding to amino acid residues 15-21 of lysozyme. These peptides broadened the antimicrobial activity of lysozyme to include Gram-negative bacteria. The results obtained in this study indicate that lysozyme possesses nonenzymatic bacteriostatic domains in its primary sequence and they are released by proteolytic hydrolysis.
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PMID:Antimicrobial peptides released by enzymatic hydrolysis of hen egg white lysozyme. 1499 3

One new isoflavone, 5,7,4'-trihydroxy-2'-methoxyisoflavone (3) and seven, and four known compounds were isolated from the barks of Crotalaria pallida and the seeds of C. assamica, respectively. The known compounds, apigenin (1) and 2'-hydroxygenistein (2), isolated from C. pallida, showed significant concentration-dependent inhibitory effects on the release of beta-glucuronidase and lysozyme from rat neutrophils in response to formyl-Met-Leu-Phe/cytochalasin B (fMLP/CB) with IC(50) values of 2.8+/-0.1 and 17.7+/-1.9, and 5.9+/-1.4 and 9.7+/-3.5 microM, respectively. The known compounds, daidzein (4) and 2'-hydroxydaidzein (6), isolated from C. pallida, inhibited of the release of lysozyme and beta-glucuronidase from rat neutrophils in response to fMLP/CB with IC(50) values of 26.3+/-5.5 and 13.7+/-2.6 microM, respectively. Compounds 1 and 4 also showed significant concentration-dependent inhibitory effects on superoxide anion generation in rat neutrophils stimulated with fMLP/CB with IC(50) values of 3.4+/-0.3 and 25.1+/-5.0 microM, respectively. Compounds 1 and 5, previously isolated from C. pallida, showed the inhibition of NO production in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and LPS/interferon-gamma (IFN-gamma)-stimulated N9 microglial cells with IC(50) values of 10.7+/-0.1 and 13.9+/-1.1 microM, respectively. Flavonoids, suppressed chemical mediators in inflammatory cells, may have value in treatment and prevention of central and peripheral inflammatory diseases associated with excess production of chemical mediators.
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PMID:Anti-inflammatory flavonoids and pterocarpanoid from Crotalaria pallida and C. assamica. 1501 12

The alpha/beta3-mixed tripeptides R-CO-beta3-HMet-Leu-Phe-OMe (1a,b), R-CO-Met-beta3-HLeu-Phe-OMe (2a,b) and R-CO-Met-Leu-beta3-HPhe-OMe (3a,b) (a, R = tert-butyloxy-; b, R = H-), analogues of the potent chemoattractant For-Met-Leu-Phe-OMe, have been synthesized by classical solution methods and fully characterized. The activities of the new analogues as chemoattractants, superoxide anion producers and lysozyme releasers have been determined on human neutrophils. Whereas all of the three N-formyl derivatives are significantly less active than the parent tripeptide as chemoattractants, compound 1b has been found to be highly active as a superoxide anion producer and 3b as a lysozyme releaser. The results show that the replacement of the native Leu residue at the central position is, in each of the examined cases, the least favourable modification. The three N-Boc derivatives are, as expected, devoid of activity as agonists, but they are all good inhibitors of chemotaxis. Information on the solution conformation has been obtained by examining the involvement of the NH groups in intramolecular H-bonds using 1H NMR. The conformation of the N-Boc analogue 1a has also been determined in the crystal state by x-ray diffraction analysis. The molecule is extended at the beta3-HMet residue (phi1 = -87 degrees; theta1 = 172 degrees; psi1 = 126 degrees) and no intramolecular H-bond is present.
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PMID:Hybrid alpha/beta3-peptides with proteinogenic side chains. Monosubstituted analogues of the chemotactic tripeptide For-Met-Leu-Phe-OMe. 1534 38

In an effort to develop potent anti-inflammatory and cancer chemopreventive agents, a series of chalcones were prepared by Claisen-Schmidt condensation of appropriate acetophenones with suitable aromatic aldehyde or prepared with appropriate dihydrochalcone reacted with appropriate alkyl bromide or prepared in one-pot procedure involving acetophenone and convenient aromatic aldehyde using ultrasonic agitation on basic alumina. The synthesized products were tested for their inhibitory effects on the activation of mast cells, neutrophils, macrophages, and microglial cells. The potent inhibitors of NO production in macrophages and microglial cells were further evaluated for their in vitro cytotoxic effects against several human cancer cell lines. 2'-Hydroxychalcones 1-3, and 2',5'-dihydroxychalcone 7 exhibited potent inhibitory effects on the release of beta-glucuronidase or lysozyme from rat neutrophils stimulated with formyl-Met-Leu-Phe (fMLP)/cytochalasin B (CB). Two 2'-hydroxychalcones (1 and 3) showed potent inhibitory effects on superoxide anion generation in rat neutrophils in response to fMLP/CB. The previously reported chalcone, 5, 6, and 12, exhibited potent inhibitory effect on NO production in lipopolysaccharide (LPS)/interferon-gamma (IFN-gamma)-activated N9 microglial cells or in LPS-activated RAW 264.7 macrophage-like cells. The potent inhibitors 5, 6, and 12 of NO production in macrophages or microglial cells revealed significant or marginal cytotoxic effects against several human cancer lines. Compound 12 manifested potent selective cytotoxicity against human MCF-7 cells and caused cell death by apoptosis. The present results demonstrated that 1-3, and 7 have anti-inflammatory effects and 5, 6, and 12 are potential anti-inflammatory and cancer chemopreventive agents.
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PMID:Synthetic chalcones as potential anti-inflammatory and cancer chemopreventive agents. 1564 15


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