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)

Microorganisms capable of producing L-pyrrolidonecarboxylate peptidase [L-pyrrolidonyl peptidase, EC 3.4.11.8] were screened and a strain of Bacillus amyloliquefaciens was chosen as one of the most potent producers of the enzyme. The enzyme was purified from lysozyme-lysate of the bacterial cells by salting out with ammonium sulfate, adsorption on DEAE-cellulose, covalent chromatography on PCMB-Sepharose and by gel filtration on Sephadex G-150. By these procedures, the enzyme was purified about 800-fold with an activity recovery of 9%, and the preparation was electrophoretically homogenous. The enzyme was most active and stable at pH 7-8. The presence of 2-mercaptoethanol and EDTA was effective for stabilizing the enzyme. The molecular weight was estimated to be 72,000 by the gel filtration method and to be 24,000 by SDS-polyacrylamide gel electrophoresis, suggesting that the enzyme is a subunit oligomer, presumably trimer. The enzyme was inactivated by the addition of PCMB, sodium tetrathionate, Hg2+ and Cu2+, but the activity lost was restored by the addition of 2-mercaptoethanol and EDTA. The purified enzyme split amide and ester linkages in L-pyroglutamyl derivatives of L-alanine, beta-naphthylamine, alpha-naphthol, and 4-methylumbelliferone, but was completely inert towards various peptides and esters used as substrates for usual amino- and carboxy-peptidases, and for endopeptidases such as trypsin, subtilisin and alpha-chymotrypsin.
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PMID:Purification and characterization of L-pyrrolidonecarboxylate peptidase from Bacillus amyloiliquefaciens. 2 93

Mycobacterium ulcerans produces an exotoxin in culture which, when inoculated into guinea pig skin, causes inflammation, necrosis, edema, and other histopathological changes resembling those in infections of humans. The toxin was resistant to heat and to alkalies and was moderately acid labile. Toxic activity was destroyed by Pronase, phospholipase, lipase, amylase, and glucosidase but not by trypsin, collagenase, cellulase, lysozyme, hyaluronidase, or neuraminidase. Toxic activity was resistant to treatment with 2-mercaptoethanol, urea, guanidine hydrochloride, p-chloromercuribenzoate, ethylenediaminetetraacetate, and sodium deoxycholate but was destroyed by sodium m-periodate and sodium dodecyl sulfate. The toxin was precipitated by a wide range of ammonium sulfate concentrations. Extraction with chlorofrom-methanol or petroleum ether destroyed its activity. Isopycnic density gradient ultracentrifugation in KBr produced a high-density lipoprotein layer with a 24-fold increase in specific activity. The results indicate that this toxin is a high-molecular-weight phospholipoprotein-polysaccharide complex.
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PMID:Further characterization of Mycobacterium ulcerans toxin. 3 Jun 94

When microsomes were prepared in 2-mercaptoethanol Vmax for 17beta-hydroxysteroid oxidoreductase (17beta-HSD) was greater, the Km for NAD+ was greater and the Km for testosterone lower than in its absence. During storage at 4 degrees Vmax increased in the presence of 2-mercaptoethanol and decreased in its absence; Km values for testosterone and NAD+ increased during storage in both cases. The presence or absence of 2-mercaptoethanol did not affect the extent or time-course of inactivation of 17beta-HSD by trypsin or phospholipase A. Furthermore, no differences were detected in sedimentation properties on sucrose density gradients suggesting that the differences and changes in the kinetic behavior of 17beta-HSD reflect a conformational flexibility at the active site and are not due to extensive changes in the structure of the microsomes. 17beta-HSD exposed to 2-mercaptoethanol was subject to substrate inhibition by testosterone, a type of inhibition not previously reported for this enzyme.
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PMID:Effects of 2-mercaptoethanol and aging in vitro on 17beta-hydroxysteroid oxidoreductase of guinea pig liver microsomes. 3 Oct 19

The alkaline phosphatase present on isolated brush border and basal lateral membranes of rat duodenal epithelium were examined by means of a variety of biochemical assays and physical methods. The two alkaline phosphatases have similar pH optima of 9.6--9.8, similar substrate km's for p-nitrophenyl phosphate (PNPP) of 71 micromolar, similar responses to the inhibitors 2-mercaptoethanol, theophylline, phenylalanine, and ethylenediaminetetraacetic acid (EDTA), similar sensitivities to calcium, magnesium, zinc, sodium, and potassium, and similar insensitivities to digestion with trypsin of papain. The two enzymes also exhibit similar molecular weights on SDS-polyacrylamide gels in the range 124,000--150,000, and both enzymes show an Rf value of 0.092 on Triton X-100 polyacrylamide gels, indicating similar intrinsic charges. The Vmax of the brush border enzyme is ten times greater than that of the basal lateral enzyme, 140 mumoles/mg-h as opposed to 14 mumoles/mg-h. The differences in Vmax are a reflection of the known distribution of alkaline phosphatase in rat duodenum, there being more alkaline phosphatase activity present on the brush border than on the basal lateral surface. One other major difference was observed between the two enzymes, the stimulation of the basal lateral and not the brush border alkaline phosphatase by SDS, Triton X-100, or cholate. We conclude that the enzymes are very similar to one another and probably perform similar membrane functions.
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PMID:Alkaline phosphatase of basal lateral and brush border plasma membranes from intestinal epithelium. 4 35

The Rho(D) antigen of red cell membranes was solubilized using ethylene-diamine tetraacetic acid (EDTA) and 2-mercaptoethanol. The solubilized antigen was partially separated from other solubilized membrane components using molecular filtration. The antigen was treated with various enzymes to learn some of the chemical characteristics. It was found that the activity of the antigen, as measured by hemagglutination inhibition, was not affected by bee venom phospholipase A, Clostridium welchii phospholipase C, calf-intestinal alkaline phosphatase, Vibrio cholerae neuraminidase, pig kidney leucine aminopeptidase, bovine pancreatic carboxypeptidase A, and pig pancreatic carboxypeptidase B. However, the proteolytic enzymes, pronase, trypsin, chymotrypsin and papain, did destroy Rho(D) activity as measured by hemagglutination inhibition. These results indicate that protein is an important part of the active determinant of the Rho(D) antigen. The experiments by other investigators have shown that lipid is important to maintain the Rho(D) activity in the intact membrane; lipid probably helps to maintain the structural conformation of the Rho(D) molecule in its natural environment. The solubilized Rho(D) molecules are apparently not dependent on lipid for their Rho(D) activity.
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PMID:Studies on the characterization of the Rho(D) antigen. 10 79

Normal human serum was shown to inhibit the mitogenic effects of bacterial lipopolysaccharide and Con A on mouse spleen lymphocytes and reduce the in vitro antibody response to SRBC by these cells. Furthermore, it was demonstrated that immune suppression occurred without loss of lymphocyte viability. Fractionation of normal human serum resulted in isolation of several immunoenhancing and immunoinhibitory fractions. Electrophoretic analysis of the immunoinhibitory fractions revealed a complex array of serum proteins. The most prominent proteins on polyacrylamide electrophoresis stained for both proteins and carbohydrate. The heterogeneity of immunoinhibitory fractions were further substantiated by their differential susceptibility to trypsin, periodate, and 2-mercaptoethanol treatment. Heterogeneity of the fractions was also shown to be related to difference in their biologic activity as expressed in their effects on mitogenicity and immunogenicity of LPS in mouse splenic cultures. This study lends evidence to the consideration that normal human serum contains several immunoregulatory factors with differing biochemical characteristics and cellular sites of action.
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PMID:Isolation and characterization of immunoregulatory factors from normal human serum. I. Preliminary biochemical and biological characterization of immunosuppressive factors. 19 Mar 15

The results of studies of the quantitative values of nonspecific antihemagglutinins of influenza viruses in the sera of birds, laboratory, wild and domestic animals (altogether 27 species) are presented. The antiviral inhibitors characterized by a number of physicochemical properties (sensitivity to heating, KIO4, trypsin, rivanol, 2-mercaptoethanol) were divided into 3 groups, sera of sheep, goats and cattle making up a separate group with regard to their sensitivity to heating and treatment with KIO4. Studies using molecular screen chromatography demonstrated the nonspecific inhibitors present in bovine sera to be heterogenous both in type (thermolabile and thermostable) and in the molecular composition. Alongside with thermolabile inhibitors of macroglobulin nature, thermostabe 19S and 4S inhibitors were identified.
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PMID:[Quantitative indices and physico-chemical properties of non-specific inhibitors of influenza A virus hemagglutination in the sera of different species of animals and birds]. 19 65

Interferon produced by rainbow trout gonadal cells (RTG-2) was partially purified. The physical, chemical, and biological properties of this in vitro produced fish cell interferon were studied. Purification was achieved by ultracentrifugation, molecular sieve gel chromatography, ion exchange chromatography, and polyacrylamide gel electrophoresis. The isoelectric point of RTG-2 interferon, as determined by CM-Sephadex (C-50) chromatography, was 7.1. Filtration through Sephadex G-150 showed that RTG-2 interferon had a molecular weight of 94,000. The partially purified material was not sedimented at 105,000 times g for 2 h at 4 C. The fish cell interferon was non-dialyzable and exhibited heat and pH stability. The partially purified material was inactivated by treatment with trypsin or 2-mercaptoethanol, but was resistant to treatment with deoxyribonuclease or ribonuclease. RTG-2 interferon which was induced by infectious pancreatic necrosis virus exhibited antiviral activity against challenge with infectious hematopoietic necrosis virus or infectious pancreatic necrosis virus. Partially purified RTG-2 interferon exhibited greater species specificity than the crude material.
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PMID:Partial purification and characterization of RTG-2 fish cell interferon. 23 93

Extracts of bovine hypothalamus were found to contain a significant level of mitogenic activity when tested in a Swiss 3T3 cell [3H]dThd incorporation assay and in a human umbilical vein endothelial cell growth assay. The mitogenic activity responsible for 3T3 cell activity was purified and characterized as a fibroblast growth factor (FGF)-like mitogen. Neither the biologically active FGF-like mitogen purified from the hypothalamus extracts nor FGF purified from bovine pituitary glands was mitogenic when added to human endothelial cells in vitro, suggesting the presence of more than one mitogen in the hypothalamic extracts. The 3T3 and endothelial cell biological activities of hypothalamic extracts were both found to be inactivated by trypsin, subtilisin, and heat treatment, but were stable to dialysis. The endothelial cell growth factor activity could be efficiently separated from the FGF activity by gel exclusion chromatography. The endothelial cell mitogen possessed a molecular weight of approximately 75,000, whereas that of FGF was approximately 15,000. The endothelial cell growth factor activity was found to be inactivated with reducing agents whereas the 3T3 cell mitogenic activity was stable after incubation with 2-mercaptoethanol. Significant levels of endothelial cell mitogenic activity were also found in extracts of bovine brain and pituitary glands.
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PMID:An endothelial cell growth factor from bovine hypothalamus: identification and partial characterization. 29 71

Limited proteolysis of bovine colostral IgG1 by trypsin caused loss of specific antibody activity but column chromatography showed that relatively little cleavage into fragements had occurred. Polyacrlamide-agarose SDS electrophoresis of the 2-mercaptoethanol-treated digest revealed, however, that extensive cleavage of light chains had occurred even though most of the material before reduction had a mol. wt close to that of undigested IgG1. Although a Fab-type fragment was detected in the digest by immunoelectrophoresis it appeared to be only a minor component. Chymotrypsin had little effect upon either the structure or antibody activity of IgG1. These findings may explain the effect of trypsin and chymotrypsin on the bactericidal activity of colostral antibodies.
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PMID:The effect of limited proteolysis by trypsin and chymotrypsin on bovine colostral IgG1. 32 43


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