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)

Human blood leukocytes and platelets and mouse peritoneal macrophages emit very rapid and very intense Luminol-dependent chemiluminescence (CL) signals when treated with streptococci, staphylococci, or with zymosan, which have been preopsonized with arginine-rich histone, dextran sulfate or polyanetholesulfonate (liquoid). Liquoid alone at 10-30 micrograms/2 X 10(5) leukocytes also triggers intense CL responses in the absence of a carrier. Strong CL can also be triggered, and at the same levels, when the various polyelectrolytes are simply mixed with the bacteria or zymosan and added to the leukocyte suspensions. The CL responses induced by the polyelectrolyte-bacteria complexes greatly exceed those triggered in leukocytes by antibody-complement-coated particles. Liquoid also shows a unique property of markedly augmenting CL signals which have already been induced by other ligand-coated bacteria or zymosan particles. Streptococci and staphylococci were found to be much superior to zymosan, Gram-positive bacilli, or E. coli as carriers for the various polyelectrolytes in the CL reaction. Neither protamine sulfate, lysozyme, myeloperoxidase, crystalline ribonuclease (all cationic in nature), chondroitin sulfate, heparin, nor alginate sulfate acted as ligands for triggering CL, when used to opsonize bacteria or zymosan. The induction of CL in blood leukocytes by the various ligand-coated bacteria is markedly inhibited by azide, KCN catalase, aminotriazole, and EDTA, agents known to inhibit the production of oxygen radicals following stimulation of leukocytes by opsonized bacteria. Two children diagnosed for chronic granulomatous diseases (CGD) of childhood and an apparently healthy sister of one of the male patients completely failed to respond with CL either to the polyelectrolyte-bacteria complexes, liquoid or antibody-coated bacteria and zymosan. It is proposed that liquoid be employed for the rapid screening of defects in certain oxygen-dependent metabolic processes in both PMNs and macrophages. It is also suggested that polyelectrolytes like the ones described in this study may markedly enhance the bactericidal properties of leukocytes and macrophages towards both extracellular and intracellular microorganisms and may perhaps also augment the tumoricidal effects of activated macrophages.
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PMID:Bacteria and zymosan opsonized with histone, dextran sulfate, and polyanetholesulfonate trigger intense chemiluminescence in human blood leukocytes and platelets and in mouse macrophages: modulation by metabolic inhibitors in relation to leukocyte-bacteria interactions in inflammatory sites. 618 6

The antigenic structural features of alpha-lactalbumin have been investigated using a radioimmunoassay, peptide inhibition of the quantitative precipitin reaction, and by immunodiffusion analysis after chemical modification of the molecule. Antigenic activity (in rabbits) was localized to several peptic fragments and the single arginine residue of bovine alpha-lactalbumin. Antigenic activity was also found to be associated with the single methionine residue. A peptic fragment containing a disulfide loop was found to possess antigenic activity in both bovine and goat alpha-lactalbumin. Radioimmunoassay cross-reactivity between the alpha-lactalbumins is correlated with amino acid sequence similarities; bovine alpha-lactalbumin antiserum cross-reacts with goat alpha-lactalbumin more extensively than with human alpha-lactalbumin, while the more distantly homologous protein, chicken lysozyme, does not cross-react at all. Nevertheless our data indicate that the alpha-lactalbumins and lysozyme share a similar distribution of antigenic determinants on their surfaces.
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PMID:Immunochemical studies on alpha-lactalbumin. 619 Dec

Protamine sulfate reversibly inhibits serum-induced mitogenic stimulation of several nontransformed and neoplastic cell types in vitro. Fifty percent inhibition was induced by approximately 120-150 micrograms protamine sulfate/ml. Cells were affected directly, and inhibition depended on the duration of cell exposure. Heparin, chondroitin sulfate, heparan sulfate, and dextran sulfate neutralized protamine sulfate effects during the early stages of treatment. Nontransformed cells [bovine aortic endothelial cells, adult human gingival fibroblasts (strains 423 and 1101), fetal rat skin (strain 921-K) and muscle fibroblasts] required longer exposure to induce inhibition than did neoplastic cells [rat 3-methylcholanthrene-induced fibrosarcoma cell lines (MCA-6 and MCA-9), a macrophage-like cell line (NCTC-3749), Walker 256 rat carcinoma cells (ATCC-CCL-38), rat Morris hepatoma cells (ATCC-CCL-144), murine melanoma cells (B16), and rat bladder squamous cell carcinoma cells (804-G)]. Other polycationic compounds, including histone type VIII-S, poly-L-lysine, poly-L-arginine, and protamine (free base), were also effective inhibitors, whereas the basic proteins cytochrome c and lysozyme had no effect. Poly-L-histidine, poly-L-glutamic acid, poly-L-aspartic acid, and dextran blue also had no inhibitory effect.
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PMID:Protamine sulfate inhibition of serum-induced mitogenic responses: differential effects on normal and neoplastic cells. 621 Mar 90

Earlier studies have indicated the marked resistance of two pronase endopeptidases to denaturation in high concentrations of urea or guanidine hydrochloride (Siegel, S., and Awad, W. M., Jr. (1973) J. Biol. Chem. 248, 3233--3240). One component has only a single residue of lysine and the other has none. The consideration arose that lysine-containing peptide segments may be less stable than those containing arginine because of the fluctuations of the side groups of the former residue. The small epsilon amino groups may not be able to sustain solvation of the hydrophobic arm in an aqueous medium. Arginine residues have shorter hydrophobic arms, larger hydrophilic groups, and higher pKa values and, thus may be less motile than lysine. The hypothesis was tested by guanidination of seven globular proteins (bovine carbonic anhydrase, chymotrypsinogen, alpha-lactalbumin, serum albumin, ribonuclease, hen egg lysozyme, and horse heart cytochrome c). Conversion of lysine residues to homoarginine was between 90 and 99%. Tritium-hydrogen isotope exchange revealed that all proteins except lysozyme demonstrated reduced out-exchange after guanidination. The results with lysozyme were not unexpected since only this protein has a high arginine to lysine ratio. These findings suggest that high arginine to lysine ratios contribute to protein stability.
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PMID:Stabilization of proteins by guanidination. 625 87

Incorporation of 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), the principal mutagen in a tryptophan pyrolysate, into bovine serum albumin was catalyzed by myeloperoxidase. Hydrogen peroxide was essential for the incorporation reaction and albumin was required for optimal incorporation of Trp-P-2 into protein. Other various proteins, such as histone, lysozyme, cytochrome c, and gamma-globulin could also incorporate Trp-P-2, but poly(L-Arg), poly(L-Lys), and poly(L-Glu) could not. The incorporation of Trp-P-2 into albumin was inhibited by L-tyrosine and L-tryptophan, but not by other amino acids. Trp-P-2 incorporated into albumin was not released from the protein by treatment with 0.3 N HCl, or 0.3 N NaOH for 2 h at 35 degrees C, or with 1% sodium dodecylsulfate for 2.5 min at 100 degrees C. On electrophoresis on polyacrylamide containing sodium dodecylsulfate or urea and on chromatography on Sepharose CL-6B in 6 M guanidine/HCl, Trp-P-2 incorporated into albumin or lysozyme migrated with these proteins. These findings indicate that Trp-P-2 is covalently bound to these acceptor proteins.
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PMID:Myeloperoxidase-catalyzed binding of 3-amino-1-methyl-5H-pyrido[4,3-b]indole, a tryptophan pyrolysis product, to protein. 625 79

A procedure for submerged culture sporulation of Streptomyces viridochromogenes and S. coelicolor is described. Activated spores were germinated in a complex medium and then shifted to a defined medium containing mineral salts and 2.5 mM L-arginine as carbon and nitrogen source. Sporulation occurred synchronously between 18-24 h incubation. An average of 10 spores were obtained from each original spore in S. viridochromogenes. The microcycle formed spores were nearly identical to surface grown spores with respect to surface morphology, dormancy, germinability and resistance to heat, lysozyme and sonication. The microcycle formed spores differed from surface spores in containing significantly less trehalose, 1.3% compared to 9.7% of the dry weight.
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PMID:Microcycle sporulation of Streptomyces viridochromogenes. 653 49

We have investigated the effect of 12 solvents and several amino acids on the fluorescence of O-(4-methylumbelliferyl)-glycosides. We showed that: i) the fluorescence quenching is not related to the dielectric constant of the solvents: the fluorescence intensity was maximal in water (d = 80) and in acetic acid (d = 6.2) and was at least ten times lower in acetone (d = 21) and in dioxane (d = 2.2); ii) the fluorescence of O-(4-methylumbelliferyl)-N-acetyl-beta-glucosaminide is not quenched in the presence of various amino acids including arginine, asparagine, aspartate, histidine, leucine, phenylalanine and proline; iii) the fluorescence of O-(4-methylumbelliferyl)-glycoside is quenched by sulfur, phenol and indole amino acids or derivatives containing sulfur, phenol or indole groups. The changes in fluorescence intensities of O-(4-methylumbelliferyl)-glycosides upon binding to concanavalin A, wheat germ agglutinin and lysozyme are discussed with regard to the amino acid content of their binding sites.
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PMID:Protein-sugar interactions: environmental effect on the fluorescence of O-(4-methylumbelliferyl)-glycosides. 668 82

Using conformational energy calculations, we previously predicted that there are two distinct binding modes for hexasaccharide substrates of hen egg white lysozyme (HEWL), a "left-sided" binding mode and a "right-sided" one. The former involves such residues as Arg-45, Asn-46, and Thr-47, while the latter involves such residues as Asn-113 and Arg-114. The left-sided binding mode was predicted to predominate for (GlcNAc)6. We now present two lines of experimental evidence that indicate that left-sided binding occurs for this substrate. First, we show that ring-necked pheasant lysozyme (RNPL), in which Lys and His replace Asn and Arg at positions 113 and 114, respectively, has the same affinity for (GlcNAc)6 as does HEWL, indicating that the "right" side is not involved in equilibrium binding to the substrate. Second, we show that a monoclonal antibody, HyHEL-5, which binds specifically to an epitope including residues Arg-45, Asn-46, Thr-47, Asp-48, and Arg-68 on the far "left" side of HEWL, is competitively displaced by (GlcNAc)5 and (GlcNAc)6 but not by GlcNAc, (GlcNAc)2, or (GlcNAc)4. Only the former two substrates can bind in site F in the lower active site. Since these two substrates are the only ones that competitively displace HyHEL-5, our results suggest that the terminal saccharide residues of these substrates bind to the left side of the active site cleft, as predicted from theory.
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PMID:Experimental identification of a theoretically predicted "left-sided" binding mode for (GlcNAc)6 in the active site of lysozyme. 671 34

Diadenosine 5',5'''-P1,P4-tetraphosphate was shown by circular dichroic measurements to bind to metal ions (Mg2+, Ca2+, Mn2+, Co2+, Zn2+), to biogenic amines (cadaverine, putrescine, spermidine, spermine), to L-arginine, to proteins (lysozyme, bovine serum albumin, Arg-rich histone f3, Lys-rich histone), and to poly(dT). Most cations effect destacking of the intramolecular adenine rings. Poly(dT) bound to the dinucleotide with a stoichiometry of 2 residues TMP per molecule of adenosine 5',5'''-P1,P4-tetraphosphate.
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PMID:Noncovalent complexes of diadenosine 5',5"'-P1,P4-tetraphosphate with divalent metal ions, biogenic amines, proteins and poly(dT). 673 84

The binding of 125I-labelled egg-white lysozyme to isolated brush border membranes of rat kidney cortex was investigated. The lysozyme binding was reversible and saturable. The Scatchard plot revealed a one-component binding type with a dissociation constant of 7.8 microM and 15.6 nmol/mg membrane protein for the number of binding sites. The binding of the basic lysozyme could be reduced by basic amino acids such as L-lysine, L-ornithine or L-arginine, while neutral amino acids such as L-citrulline or L-alanine had no effect. The inhibitory effect of lysine was competitive.
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PMID:Binding of lysozyme to brush border membranes of rat kidney. 687 Dec 5


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