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

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

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

Quantitative estimation of native and treated with 4% formaldehyde albumin, pepsin, lysozyme, histone, gelatin and other proteins was carried out using four procedures--biurete, Lowry-Folin, ninhydrin and coomassy R-250. Chromogeneity of proteins in corresponding color reactions was expressed as OD per 100 micrograms of nitrogen estimated by means of Kjeldahl micromethod. The proteins were treated with formaldehyde in corresponding buffers at 20 degrees within 7 days, non-bound or loosely bound formaldehyde was dialysed. Native proteins were dissimilar in their chromogeneity; these differences were the highest for Lowry-Folin and coomassy procedures. Formalinization affected the protein chromogenencity depending on a protein nature, conditions of formaldehyde treatment and on the procedure of estimation used. As shown by analysis of the data obtained the alterations of chromogeneity did not reflect the rate of reactive group blocking by formaldehyde in a protein molecule. The quantitative methods should be used very carefully in estimation of formalinized proteins.
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PMID:[Estimation of various quantitative methods for the determination of native and formaldehyde-treated proteins]. 640 1

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

Various polyelectrolytes were investigated regarding their capacity to inhibit the binding of human IgG to Fc-receptors on group A streptococci, type M1. Of cationic substances, protamine and arginine-rich histone inhibited significantly, while lysine-rich histone, concanavalin A, lysozyme, polymyxin B, ribonuclease and tuftsin did not. Of anionic materials, liquoid was inhibitory, in contrast to chondroitin sulphate, dextran sulphate, DNA and heparin. Washing experiments showed that the inhibition was caused by binding of the polyelectrolytes to the streptococci. The finding that heated IgG inhibited the binding of histone to the streptococci also indicated a close relation between the binding sites for these compounds. Diffusion-in-gel experiments with alkaline extract of M1 demonstrated that the substances blocking the IgG Fc-receptor were bound to polyglycerophosphate, suggesting that the inhibition of the IgG uptake was due to interaction with lipoteichoic acid. Leukocyte and platelet extracts could modify the binding of IgG, probably by an enzymatic digestion of the receptors. The arginine-rich histone was also capable of inhibiting the binding of IgG to type M15 group A streptococci and to one group G strain. However, the polyelectrolytes had no effect on the binding of IgG to Staphylococcus aureus or of IgA to type 4 group A streptococci.
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PMID:Cationic polyelectrolytes, liquoid and leukocyte extract modulate the binding of IgG to group A streptococcal Fc-receptors. 704 38

Exogenous calf thymus whole histones showed a high degree of specificity to cause agglutination of rat epididymal spermatozoa. Histones had markedly greater (approximately 5-fold) agglutination activity than did salmon protamine whereas a variety of proteins, including strongly basic ones such as herring protamine sulphate, ribonuclease, cytochrome C and lysozyme, had no detectable agglutination activity. Histones F-3 and F-2a had the greatest activity for cell agglutination. Polyamines (5 mM), sialic acid (5 mM) and basic or acidic amino acids (10 mM) had no effect on histone (approximately 8 microM)-mediated sperm agglutination. 32P-Labelled histones showed a high specificity for binding to intact spermatozoa. The binding was saturable at a histone concentration of approximately 0.3 mg/ml and nearly completely displaced at saturating concentrations of native histones. Only unlabelled protamines competed to a small extent for binding of 32P-labelled histones to spermatozoa. The data are consistent with the view that histones bind specifically to sperm surface receptor sites before agglutination of cells.
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PMID:Histone-mediated agglutination of epididymal spermatozoa and the occurrence of histone receptors on the rat sperm surface. 725 26

The major proteins in the lumen of the endoplasmic reticulum (ER) are thought to function in Ca2+ sequestration or as "molecular chaperones" in the folding and assembly of membrane or secreted proteins. Based on the ability of many chaperones to bind selectively to unfolded proteins and to dissociate from them upon ATP hydrolysis, we developed an affinity chromatography method to isolate proteins with these characteristics from pancreatic or liver ER. Seven ER proteins bound selectively to denatured protein columns and were specifically eluted by ATP (10(-6) M) but not by a nonhydrolyzable ATP analog. These proteins were identified with antibodies and microsequencing as the ER chaperone BiP (grp78), grp94, calreticulin, a novel 46-kDa protein that binds azido-ATP, as well as three members of the thioredoxin superfamily: protein-disulfide isomerase, ERp72, and a previously reported 50-kDa protein (p50). This set of seven proteins bound to and was eluted with ATP from a variety of denatured proteins, including histone, gelatin, alpha fetoprotein, thyroglobulin, lysozyme, casein, and IgG. The release of grp94, protein-disulfide isomerase, ERp72, calreticulin, and p50 was stimulated by Ca2+ in the presence of ATP. These proteins thus appear to function as Ca(2+)-dependent chaperones, which may account for the Ca2+ and ATP requirement for protein folding in the ER.
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PMID:A set of endoplasmic reticulum proteins possessing properties of molecular chaperones includes Ca(2+)-binding proteins and members of the thioredoxin superfamily. 829 23

51Chromium-labeled rat pulmonary artery endothelial cells (EC) cultivated in MEM medium were killed, in a synergistic manner, by mixtures of subtoxic amounts of glucose oxidase-generated H2O2 and subtoxic amounts of the following agents: the cationic substances, nuclear histone, defensins, lysozyme, poly-L-arginine, spermine, pancreatic ribonuclease, polymyxin B, chlorhexidine, cetyltrimethyl ammonium bromide, as well as by the membrane-damaging agents phospholipases A2 (PLA2) and C (PLC), lysolecithin (LL), and by streptolysin S (SLS) of group A streptococci. Cytotoxicity induced by such mixtures was further enhanced by subtoxic amounts either of trypsin or of elastase. Glucose-oxidase cationized by complexing to poly-L-histidine proved an excellent deliverer of membrane-directed H2O2 capable of enhancing EC killing by other agonists. EC treated with rabbit anti-streptococcal IgG were also killed, in a synergistic manner, by H2O2, suggesting the presence in the IgG preparation of cross-reactive antibodies. Killing of EC by the various mixtures of agonists was strongly inhibited by scavengers of hydrogen peroxide (catalase, dimethylthiourea, MnCl2), by soybean trypsin inhibitor, by polyanions, as well as by putative inhibitors of phospholipases. Strong inhibition of cell killing was also observed with tannic acid and by extracts of tea, but less so by serum. On the other hand, neither deferoxamine, HClO, TNF, nor GTP gamma S had any modulating effects on the synergistic cell killing. EC exposed either to 6-deoxyglucose, puromycin, or triflupromazin became highly susceptible to killing by mixtures of hydrogen peroxide with several of the membrane-damaging agents. While maximal synergistic EC killing was achieved by mixtures of H2O2 with either PLA2, PLC, LL, or with SLS, a very substantial release of [3H]arachidonic acid (AA), PGE2, and 6-keto-PGF occurred only if a proteinase was also added to the mixture of agonists. The release of AA from EC was markedly inhibited either by scavengers of H2O2, by proteinase inhibitors, by cationic agents, by HClO, by tannic acid, and by quinacrin. We suggest that cellular injury induced in inflammatory and infectious sites might be the result of synergistic effects among leukocyte-derived oxidants, lysosomal hydrolases, cytotoxic cationic polypeptides, proteinases, and microbial toxins, which might be present in exudates. These "cocktails" not only kill cells, but also solubilize AA and several of its metabolites. However, AA release by the various agonists can be also achieved following attack by leukocyte-derived agonists on dead cells. It is proposed that treatment by "cocktails" of adequate antagonists might be beneficial to protect against cellular injury in vivo.
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PMID:Killing of endothelial cells and release of arachidonic acid. Synergistic effects among hydrogen peroxide, membrane-damaging agents, cationic substances, and proteinases and their modulation by inhibitors. 833 Sep 29

An instrument for continuous-flow quasielastic light scattering is described that allows the translational diffusion coefficient of macromolecules to be determined as a function of time after the initiation of some time-dependent process by mixing. Control experiments are carried out using the proteins lysozyme and BSA to verify that flow of the solution does not lead to erroneous results. The instrument is used to determine the lifetime of the histone octamer. A solution of octamer that is artificially stabilized in 2.0 M NaCl is rapidly diluted to physiological ionic strength, and the Stokes diameter is determined as a function of the time, delta t, after mixing. We find that the octamers dissociate into their component H2A-H2B heterodimers and H(3)2H4 tetramers on a time scale that is faster than the earliest time point for which data were obtained, 1 s after mixing. This result argues against a simple mechanism for the progression of RNA or DNA polymerase through chromatin.
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PMID:Lifetime of the histone octamer studied by continuous-flow quasielastic light scattering: test of a model for nucleosome transcription. 834 88


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