Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

When the jelly-less eggs removed from the most cephalic region of the oviduct (pars recta) of the toad Bufo arenarum were inseminated at a high sperm concentration, high frequencies of fertilization were obtained. On the other hand, control eggs removed from the pleuroperitoneal cavity (coelomic eggs)) were neither fertilized upon insemination under identical conditions, nor with the water extract of the jelly. Under these inseminating conditions, however, a high frequency of fertilization was obtained when coelomic eggs were preincubated in the presence of the fluid secreted by the epithelium of the pars recta or of an extract prepared from pars recta homogenate. Experimental evidence is presented showing that the component responsible for this effect acts on the vitelline envelope of the egg, increasing its susceptibility to sperm lysin. It is probable, therefore, that it induces successful fertilization of coelomic eggs by making the vitelline envelope more easily penetrable by sperm. The active factor was partially purified by Sephadex chromatography. The product obtained was of high activity and, as judged by its inhibition with soybean trypsin inhibitor and lima-bean trypsin inhibitor, it is likely to be a trypsin-like enzyme. The molecular weight of the factor was estimated to be 47000 by Sephadex chromatography. Secretion of the pars recta factor is hypophysis-dependent and its activity is not influenced by pH within the range testes (6.0--8.4).
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PMID:A trypsin-like oviducal proteinase involved in Bufo arenarum fertilization. 3 7

Exposure of rabbit ova to wheat germ agglutinin (WGA) at a concentration of 50 microgram/ml for 30-45 min rendered the zona pellucida at least 10 times more resistant to digestion by 1 mg trypsin/ml, and also more resistant to acrosin. Nevertheless, the zonas of WGA-treated eggs were penetrated by spermatozoa as readily as those of untreated eggs in the same oviduct. These results suggest that penetration of spermatozoa through the zona pellucida may not require the agency of a trypsin-like enzyme acting as a primary zona lysin. The validity of the general belief that a lysin in necessary for zona penetration is considered briefly in relation to the mode of penetration and structural organization of the mammalian sperm head.
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PMID:Normal penetration of rabbit spermatozoa through a trypsin- and acrosin-resistant zona pellucida. 36 50

The substituent dependence for kcat/Km of trypsin anilide hydrolysis is consistent with a rate-limiting general acid-base catalysed breakdown of a tetrahedral intermediate. The formation and disappearance of this intermediate during the hydrolysis of alpha-N-acetyl-L-lysin p-nitroanilide is observed in stopped-flow experiments.
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PMID:Detection of a tetrahedral intermediate in the trypsin-catalysed hydrolysis of specific ring-activated anilides. 56 21

The release of beta-lysin, which followed the intravenous injection of antigen-antibody complexes, did not take place when these complexes were added to citrated whole blood but did occur in heparinized blood. beta-Lysin release in heparinized blood was inhibited by citrate but were reversed by the addition of calcium ions that implicated complement reactions. Fourteen different enzymes were added to platelet-rich plasma (PRP). Streptokinase, neuraminidase, papain, phospholipase C, sulfatase, and trypsin caused platelets to release significant quantities of beta-lysin, whereas elastase, phosphatase, protease, ribonuclease A, hyaluronidase, lipase, and pepsin caused little or no increase in the plasma beta-lysin concentration. One enzyme, fibrinolysin, inactivated beta-lysin faster than it was released. The enzyme-induced release of beta-lysin from PRP was often accompanied by a reduction in the number of platelets. The intravenous injection of streptokinase, neuraminidase, and sulfatase caused in vivo releases of beta-lysin into the plasma. The platelet-aggregating substances collagen, arachidonic acid, and adenosine 5'-diphosphate caused beta-lysin to be released from PRP. The platelet-aggregating substances L-epinephrine, zymosan, fibrinogen, reserpine, and serotonin caused little or no release of beta-lysin from platelets. The results of this study indicate that the release of beta-lysin during antigen-antibody-complement reactions, blood coagulation, phagocytosis, and inflammation could be enzyme mediated.
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PMID:Release of beta-lysin from platelets caused by antigen-antibody complexes, purified enzymes, and platelet-aggregating substances. 84 4

The method of high-voltage paper electrophoresis may be applied not only for peptide separation, but also in modifications and combinations with other methods, so, by means of aminoethylation and maleylation it is possible to broaden or narrow the range of trypsin action. This, in its turn, makes it possible to isolate preparatively lysin- and arginine-containing peptides, oxidation with performic acid enables the thyol-containing fragments to be isolated and application of carboxypeptidase A-C-terminal peptide of protein. When studying the primary structure of proteins the method has already found its widest application but with an increase in the number of methods of protein specific modification its potentiabilities will be even wider.
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PMID:[High-voltage electrophoresis and its application in combination with other methods for protein structure studies]. 121 56

gamma-Lysin was purified from Staphylococcus aureus strains Smith 5R and PG23 (a toxic shock syndrome isolate) by a combination of heparin-agarose and hydroxylapatite chromatography. Both strains produced two haemolytic components, designated gamma 1 and gamma 2. Though each component was weakly haemolytic they acted synergistically to potentiate haemolysis on rabbit, sheep and human blood. Rabbit and sheep erythrocytes were more sensitive to lysis by gamma-lysin than human erythrocytes. The molecular mass of gamma 1 was 32 kDa and its pI value was 9.4. gamma 2 had a molecular mass of 36 kDa and a pI value of 9.3. While both trypsin and papain acted synergistically with gamma 2 to induce increased haemolysis, no such synergism was seen with gamma 1. Also, protease inhibitors acted to inhibit synergism between gamma 1 and gamma 2. These findings suggest that gamma 1 could be a protease.
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PMID:Characterization of staphylococcal gamma-lysin. 164 29

In Ciona intestinalis, sperm penetration through the egg vitelline coat is an essential event of fertilization. We investigated whether trypsin- and chymotrypsin-like enzymes are involved in this event. Inhibitors and peptide substrates for chymotrypsin-like enzymes blocked the overall process of fertilization in a concentration-dependent manner. The inhibitory activity was specifically exerted on the step of sperm penetration. Chymotrypsin-like protease activity was identified in spermatozoa with the fluorogenic synthetic substrate Suc-Ala-Ala-Phe-AMC, which was the most effective substrate in blocking sperm penetration. These data indicate that a chymotrypsin-like protease activity is a sperm lysin of Ciona intestinalis.
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PMID:Chymotrypsin-like enzymes are involved in sperm penetration through the vitelline coat of Ciona intestinalis egg. 222 80

DNA sequence analysis of the complete M6 protein gene revealed 19 hydrophobic amino acids at the C terminus which could act as a membrane anchor and an adjacent proline- and glycine-rich region likely to be located in the cell wall. To define this region within the cell wall and its role in attaching the molecule to the cell, we isolated the cell-associated fragment of the M protein. Assuming that the cell-associated region of the M protein would be embedded within the wall and thus protected from trypsin digestion, cells were digested with this enzyme, and the wall-associated M protein fragment was released by phage lysin digestion of the peptidoglycan. With antibody probes prepared to synthetic peptides of C-terminal sequences, a cell wall-associated M protein fragment (molecular weight, 16,000) was identified and purified. Amino acid sequence analysis placed the N terminus of the 16,000-molecular-weight fragment at residue 298 within the M sequence. Amino acid composition of this peptide was consistent with a C-terminal sequence lacking the membrane anchor. Antibody studies of nitrous acid-extracted whole bacteria suggested that, in addition to the peptidoglycan-associated region, a 65-residue helical segment of the C-terminal domain of the M protein is embedded within the carbohydrate moiety of the cell wall. Since no detectable amino sugars were associated with the wall-associated fragment, the C-terminal region of the M6 molecule is likely to be intercalated within the cross-linked peptidoglycan and not covalently linked to it. Because the C-terminal region of the M molecule is highly homologous to the C-terminal end of protein A from staphylococci and protein G from streptococci, it is likely that the mechanism of attachment of these proteins to the cell wall is conserved.
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PMID:Isolation and characterization of the cell-associated region of group A streptococcal M6 protein. 245 2

In a series of experiments the influence of the trypsin inhibitors aprotinin (Trasylol) and TLCK (N-p-tosyl-L-lysin chloromethyl ketone) on the gelatinolytic activity of acrosin and motility of rabbit spermatozoa was tested. Ejaculated, highly motile spermatozoa were washed in Brackett-Medium. 12.5 to 1000 microns Aprotinin and 50 to 1000 micrograms TLCK, respectively, were added to samples of 1 ml sperm suspension: the specimens were incubated at 37 degrees C. Increasing aprotinin concentrations reduced the gelatinolytic activity of acrosin and the sperm incubation at a concentration of 1000 micrograms Aprotinin/ml sperm. Spermatozoa in all TLCK specimens were entirely immotile 1.5 hours after incubation. The gelatinolytic activity of acrosin was obviously not inhibited at any TLCK concentration. These results suggest that, under these experimental conditions, aprotinin and TLCK may impair primarily the motility spermatozoa.
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PMID:[The effect of the trypsin inhibitor aprotinin (Trasylol) and TLCK on the gelatinolytic activity of acrosin and the motility of rabbit sperm in vitro]. 247 24

Three different enzymatic extraction procedures were tested for their effectivity in releasing IgG-binding peptides from the streptococcal cell wall. Streptococcus equisimilis strain 12628 isolated from pig was incubated with phage-associated lysin, trypsin and Streptomyces globisporus lytic enzyme and the extracts were investigated by Western blotting, indirect erythrocyte agglutination and Ouchterlony diffusion for IgG-binding activity. With all treatments IgG-binding peptides were extracted. However, no homogenous IgG-binding material was released by the enzymes tested. In each case a multiple peptide pattern with IgG-binding activity was found. The molecular weights of the active peptides released also differed between the extraction procedures. The isoelectric points between 4.0 and 4.3 of IgG-binding components were found to be similar for all three extracts.
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PMID:Extraction of group C streptococcal IgG-binding receptor and characterization of the active peptides by Western blotting and isoelectric focusing. 296 Jan 5


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