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)

A virus, which was isolated from kids (Capra hircus) affected with a relatively severe generalized infection, was found to contain DNA and to have a buoyant density of 1.2820 g/cm3. The virus was sensitive to the action of lipid solvents and trypsin and was rapidly inactivated at pH 3.0 and at temperatures of 50 and 56 C. The virion, an icosahedron consisting of a nucleoid surrounded by a double membrane, measured approximately 135 nm in diameter. On the basis of its chemical and physical properties, the virus is considered a herpesvirus.
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PMID:Characterization of a caprine herpesvirus. 0 Sep 33

The NADP-specific glutamate dehydrogenase of Neurospora crassa was digested with trypsin, and peptides accounting for 441 out of the 452 residues of the polypeptide chain were isolated and substantially sequenced. Additional experimental detail has been deposited as Supplementary Publication SUP 50052 (11 pages) with the British Library (Lending Division), Boston Spa, Wetherby, W. Yorkshire LS23 7BQ, U.K., from whom copies may be obtained under the terms given in Biochem J. (1975) 145, 5.
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PMID:The amino acid sequence of Neurospora NADP-specific glutamate dehydrogenase. The tryptic peptides. 0 Oct

A kinetic study of procine chymotrypsin A-pi revealed two characteristic properties of this type of chymotrypsin: 1. Porcine chymotrypsin A-pi, like bovine chymotrypsin B-pi does not bind proflavin, which is a competitive inhibitor of bovine trypsin and chymotrypsin A-alpha. 2. The pH profiles of the steady-state parameters show the two usual important pK's. The basic one, pK2 = 9.6, affects both Km and kcat/Km and probably controls the binding conformation of chymotrypsin. The acidic one, pK1 = 5.7, affects kcat and kcat/Km and plays a role in the catalytic process. The value of pK1 is unusually low.
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PMID:Porcine chymotrypsin A-pi, a more acidic chymotrypsin. 0 Nov 43

Chymotrypsinogen has been successfully renatured in solution, after reduction of its 5 disulfide bonds in 6 M guanidine-HCl. This has been made possible by the study of the renaturation of a model derivative, polyalanyl-chymotrypsinogen. The reduced derivative is shown to refold and reoxodize spontaneously, with a 30-40% yield, into molecules which are monomeric and fully susceptible to activation by trypsin. Chymotrypsinogen can also be renatured but only in the presence of reagents allowing disulfide interchange and of moderate concentrations of guanidine-HCl or urea. These results illustrate how the kinetic trapping of incorrectly folded molecules by wrong S-S bonds and aggregation can be overcome, thus allowing the correct refolding of the protein.
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PMID:The renaturation of reduced polyalanyl-chymotrypsinogen and chymotrypsinogen. 0 Dec 54

From a crude extract of chick peas (Cicer arietinum L.) inhibitors of trypsin and chymotrypsin were isolated by affinity chromatography on a column of trypsin-Sepharose 6B. The content of inhibitors was found to be 1.5 g/kg. They were further separated into six isoinhibitors by ion-exchange chromatography on DEAE-Sephadex A-25. Two of the isoinhibitors accounted for about 50% of the isolated inhibitors and were further purified to a homogeneous state. The isoinhibitors had a molecular weight of about 10000 as determined by molecular-sieve chromatography on Sephadex G-75. They were stable towards extremes of pH and temperatures up to 75 degrees C or towards digestion by pepsin. They were also stable in 6 M urea but not in 6 M guanidine-HCl. The intact inhibitors were destroyed when the peas were cooked at 100 degrees C or when they were toasted at 130 degrees C. The four major inhibitors had similar amino acid compositions and did not contain detectable amounts of free sulfhydryl groups, tryptophan or carbohydrate. Cysteine is the dominant amino acid residue in all of them and accounted for about 20% of their amino acid content. The isoelectric point of the isoinhibitors lies in the range of pH 4.9-8.6 and two of the major inhibitors had isoelectric points of pH 4.75 and pH 4.96. They inhibited chymotrypsin to the same extent but differed in their inhibitory activities towards trypsin, indicating that they are mixtures of native and trypsinmodified forms and that they probably have separate sites for the two enzymes. They did not inhibit other proteolytic enzymes belonging to two groups (i.e., serine or cysteine enzymes) or originating from different sources (i.e., animals, plants or bacteria).
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PMID:The trypsin and chymotrypsin inhibitors in chick peas (Cicer arietinum L.). Purification and properties of the inhibitors. 0 Dec 66

The extracts of granules of human polymorphonuclear leukocytes hydrolyzed a variety of proteins including human and bovine hemoglobin, human fibrinogen, human and bovine serum albumin, bovine elastin, and casein. The hydrolysis of all the proteins except fibrinogen and elastin was increased by addition of urea. Various inhibitors of trypsin, kallikrein, plasmin, Clr, Cls, and other proteolytic enzymes had no inhibitory effect. Slight inhibition was observed with polyanethol sulfonate and strong inhibition with normal human serum. Serum of patients with hereditary angioneurotic edema having no functional C1-esterase inhibitor was as effective in inhibiting the proteolysis as normal serum. The inhibitor was localized in 4S fractions of normal serum fractionated on Sephadex G-200. Fractionation of normal serum by ammonium sulfate precipitation, Sephadex G-200 filtration, and CM-Sephadex chromatography did not result in appearance of inhibitory activity in more than one protein peak, suggesting the possibility that only one inhibitor might be responsible. Since all fractions which contained the inhibitor of proteolysis also contained alpha1-antitrypsin, since sera of patients having low alpha1-antitrypsin levels contained less inhibitory activity, and since antibodies against alpha1-antitrypsin reversed the inhibition obtained from normal serum, the inhibition of proteolysis may be attributed to alpha1-antitrypsin.
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PMID:Some properties of proteolysis by polymorphonuclear leukocyte-granule extracts. 0 49

This report describes macromolecules that bind (des-aspartic acid1)-angiotensin II, the des aspartic acid1 derivative of angiotensin I, and several biologically active and inactive analogues of these polypeptides. The macromolecules were found in the plasma of approximately 2 per cent of ambulatory adults and hospitalized children and 32 per cent of the patients at two institutions for the mentally retarded. The binding properties of these macromolecules were studied by incubating with peptides labeled with 125iodine, and separating bound from free labeled peptide using small gel filtration columns. The peptide-binding macromolecules from several patients were compared. They showed very similar specificity for a group of arginyl peptides of the des-aspartyl1-angiotensin sequence. The plasma binders differed from one another in their optimum pH and their mobility in electrophoretic fields. Those with more acid pH optima displayed more rapid electrophoretic mobility. The binders fell into two classes based on apparent molecular weight, approximately 140,000 and 250,000. Those with the higher apparent molecular weight contained a large proportion of binder that could be precipitated with antiserum to human IgA. Kinetic measurements showed that the plasma binders were somewhat heterogeneous with respect to affinity for (des-asp1)-angiotensin, with apparent association constants ranging from 10(7) to 10(8) M-1. Binding activity was labile to heat, and to treatment with pepsin or trypsin. It was inhibited by calcium, protamine, streptomycin, and some other cationic compounds. The plasma peptide binder differed in specificity and molecular weight from soluble angiotensin-binding molecules extracted from tissues, and from properties expected of a receptor for angiotensin. These macromolecules may be useful reagents for measuring (des-asp1)-angiotensins. Their presence in plasma samples may interfere with angiotensin assays in some circumstances.
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PMID:Peptide-binding macromolecules in the blood of seriously ill or mentally retarded patients. 0 55

Strains of transmissible gastroenteritis (TGE) virus possessing different pathogenicity were examined for stability to digestive enzymes and acid, and growth at various temperatures. In growth experiments, virus titer obtained at 37 degrees C were about equal between attenuated and virulent strains, but titers attained by the attenuated strain were higher at 30 degrees C. The attenuated virus multiplied at 28 degrees C, but the virulent virus did not at this temperature. The virulent virus was significantly stable to trypsin and pepsin, but the attenuated virus was inactivated rapidly by these proteolytic enzymes. No significant differences were observed in stability to acid between the attenuated and virulent strains. At different pH, both lost their infectivity more rapidly at 37 degrees C than at 22 degrees C.
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PMID:Comparison of properties between virulent and attenuated strains of transmissible gastroenteritis virus. 0 84

The formation of an insoluble product of the interaction of trypsin and sodium alginate at pH 3-9 was studied. The optic density of the system was in an extreme relation to the composition. The insoluble phase was enriched in trypsin. The dispersion phase formed as a result of the electrostatic interaction between alginate macroanion and trypsin macrocation. The interaction brought about the formation of ATn, where n=90-900 (with an accuracy of the term Mw/Mn of alginate). The relation between the composition of the complex and pH was nonmonotonous.
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PMID:[Trypsin interaction with sodium alginate]. 0 25

Immobilized trypsin and alpha-chymotrypsin were obtained as a result of the enzyme attachment to bromo-cyanogen activated cepharose. Proteolytic activity (substrate--casein) of immobilized trypsin and alpha-chymotrypsin was 18.7 and 9%, respectively and their esterase activity with methyl ester benzoyl-L-arginine (trypsin) and ethyl ester acetyl-L-tyrosine (alpha-chymotrypsin) was 75 and 20% of that of soluble enzymes. Immobilized enzymes were used to purify proteinase inhibitors from potatoes by affine chromatography. Specific activity of trypsin and chymotrypsin inhibitors was increased 10 and 6 times, respectively. By isoelectric focussing it was shown that the purified preparation of chymotrypsin inhibitors consisted of two acid proteins and one alkaline protein, the latter being in predominance. The purified preparation of trypsin inhibitors contained equal amounts of proteins with the isoelectric point at pH 7.1 and 8.9 and a low quantity of the component with the isoelectric point at pH 5.7.
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PMID:[Properties of immobilized trypsin and alpha-chymotrypsin and their use for purification of proteinase inhibitors from potatoes]. 0 33


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