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:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Limited proteolysis of myosin by such proteolytic enzymes as trypsin, chymotrypsin or papain produces typical fragmentation of its heavy chain. Presently evidence is given that trypsin treatment cleaves the alkali light chain A-1 (20,700 dalton) to a shorter (ca 20,000 dalton) chain. The two "essential" thiols (SH-1 and 2) of moysin were alkylated with 17-C-N-ethylmaleimide and a non-negligible amount of radioactivity was also found in the two alkali light chains. Using the specific radioactivity of alkali light chain A-1 it was possible to identify it among heavy chain fragmentation products. The molecular weight of the newly formed A-1 indicates that limited tryptic cleavage of this A-1 confers on it a closer similarity with alkali light chain A-2.
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PMID:[Fragmentation of myosin A-1 light chain of fast muscle by trypsin]. 11 21

Highly purified A-1-A.T., prepared from blood obtained from donors of known PiZZ and PiMM phenotype, was radiolabeled with 125I or 131I and injected intravenously into dogs. The radiolabeled proteins retained their prelabel electrophoretic and trypsin-inhibitory characteristics. The biologic t1/2 of both M and Z protein in the circulation were similar, averaging 71 hr for M protein and 80 hr for Z protein. The label was shown to remain tightly bound in vivo for 2 days after injection. The material was nonpyrogenic in rabbit and dog. No arteriovenous differences in radioactivity could be detected at 2 or 20 min after injection. However, surface scanning disclosed substantial pulmonary deposition of radioactivity for the first 9 hr after injection. At 48 hr, intense radioactivity was present in the spleen, but not in the liver. These studies indicate the feasibility of similar studies in man, including noninvasive assessment of body distribution of M and Z protein by surface scanning techniques.
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PMID:Biologic half-life and organ distribution of radiolabeled human PiM and PiZ alpha-1-antitrypsin in the dog. 30 68

Bovine and porcine pancreatic residue, remaining after the extraction of insulin, has been used to prepare a proteinase powder. This powder was used as a source of trypsin and chymotrypsin. The individual enzymes were isolated and purified by chromatography on sulfopropyl (SP) - Sephadex C-25 and affinity chromatography on soybean trypsin inhibitor (STI) - Sepharose. The bovine proteinase powder contained alpha-chymotrypsin, trypsin and chymotrypsin B in the ratio 5 : 2 : 1. The porcine powder contained cationic trypsin, anionic trypsin and cationic chymotrypsin in the ratio 5 : 1.4 : 3. The isolated enzymes were characterized and found to be identical with enzymes isolated from fresh tissue with the exception of porcine chymotrypsin. Porcine cationic chymotrypsin was isolated as two distinct forms, A-1 and A-2, which appear to be different activation products of porcine chymotrypsinogen A. Both forms resemble bovine alpha-chymotrypsin, a three chain structure, rather than porcine chymotrypsin Api, a two chain structure. Futhermore, the B-chain appears to be cleaved, possibly at residues Phe89-Lys90.
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PMID:The preparation of trypsins and chymotrypsins from bovine and porcine residues after insulin extraction. 56 86

1. High-affinity estrogen-binding sites can be solubilized from the liver chromatin of estrogenized chickens by treatment of the chromatin with 2 M KCL/5 M urea and fractionation on hydroxylapatite. Two estrogen-binding proteins are eluted from hydroxylapatite columns by 20mM phosphate (binding protein I) and 200mMphosphate (binding protein II), respectively. 2. The binding protein I is part of a non-histone protein fraction containing acid-soluble and insoluble proteins, whereas the binding protein II elutes together with high molecular weight nonhistone proteins containing acid insoluble proteins only. Both binding proteins exhibit the smae affinity for estradiol (Kd approximately 10(-9) M). 3. From chromatin of untreated chickens very small amounts of binding protein I (0.1 pmol/mg protein compared to 1.9 pmol/mg protein from estrogenized chickens) with the smae affinity for estradiol as that from estrogenized animals can be solubilized. Binding protein II is not detectable. 4. The "soluble nuclear estrogen receptor" extracted from crude liver nucleir of estrogenized chickens by 0.5 M KCL behaves on hydroxylapatite very similarly to salt/urea-dissociated chromatin with respect to the binding protein I. No binding protein II, however, can be demonstrated. 5. Chromatography of various preparations on Bio-Gel A-1.5 m indicates that the binding protein II is a residual chromatin fragment containing an unseparated binding protein-DNA complex, whereas the binding protein I represents the solubilized nucleic-acid-free chromosomal estrogen receptor. The "soluble nuclear receptor" and the binding protein I, however, are not identical with respect to their chromatographic behaviour on Bio-Gel A-1.5m, even though their estrogen binding entity remaining after trypsin treatment seems to be very similar.
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PMID:Solubilization of the chromatin-bound estrogen receptor from chicken liver and fractionation on hydroxylapatite. 96 52

Binding of a denaturated polypeptide chain derived from chick skin collagen, the alpha 1(I) chain, by isolated membranes of human platelets has been demonstrated. The process is reversible, and time- and protein concentration-dependent. The binding is specific, with an association constant of 1.88 X 10(-6) M. Prior treatment of the isolated membranes with trypsin, chymotrypsin, and pronase, resulted in significant inhibition of the 14C-labeled alpha 1 chain binding, but neuraminidase or collagenase treatment had no effect. Dissociation of the bound radioactivity and subsequent chromatographic analyses on carboxymethylcellulose and agarose A-1.5m revealed that the alpha 1 chain was unaltered. Scatchard plot analysis suggested that there are approximately 20,000 binding sites per platelet. The binding of the alpha 1 chain was inhibited by a glycopeptide derived from alpha 1, alpha 1-CB5 and by purified glucosylgalactosyl hydroxylysine, but was not affected by other cyanogen bromide peptides of alpha 1, namely alpha 1-CB3, -CB4, -CB7, and -CB8. Kinetic studies demonstrated that inhibition by the hydroxylysine glycoside is competitive. Dose-response curves of platelet aggregation induced by alpha 1 and the binding of alpha 1 by platelet membranes correlate closely. These results indicate that there are specific binding sites for collagen alpha 1 chain on platelet membranes, and that the carbohydrate moiety of the alpha 1 chain plays a role in the binding. The findings also support the hypothesis that the chick skin alpha 1 chain mediates platelet aggregation and the release reaction by acting on platelet membranes.
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PMID:Binding of chick skin collagen alpha 1 chain by isolated membranes from human platelets. 97 74

Transcarboxylase is made up of a central hexameric subunit (S20,W similar 12 S), three peripheral dimeric metallo subunits (S20,W similar to 5 S), and six biotinyl carboxyl carrier subunits (S20,W similar to 1.3 S). The results presented here show that the carboxyl carrier subunit is required for assembly of the 12S and 5S subunits into the oligomer. However, only a portion of the subunit is required for assembly. On treatment of transcarboxylase briefly with trypsin at pH 6.3 extremely susceptible peptide bonds of the carboxyl carrier protein are cleaved releasing biotinyl peptides of about similar to 66 and similar to 40 residues. The resulting trypsinized transcarboxylase, though enzymatically inactive, remains essentially intact as judged by its hydrodynamic and molecular sieving properties. The modified enzyme can be dissociated at pH 8 to the central 12S subunit and peripheral 5S subunit to which the residual portion(s) of the cleaved carboxyl carrier protein is still attached. These components can then be separated by molecular sieving. The residual portion of the carboxyl carrier protein (non-biotinyl peptide) can then be isolated by dissociation of the 5S subunit complex at pH 9 and by chromatography over Bio-Gel A-1.5m. The isolated non-biotinyl peptide has been shown to contain the combining domain of the 1.3SE carboxyl carrier protein since it causes combination of the 12S and 5S subunits. Active enzyme is formed by combination of the intact carboxyl carrier protein and the 12S and 5S subunits and an inactive oligomer of similar size is formed if the non-biotinyl peptide is used in place of the carboxyl carrier protein. The similar to 66- and similar to 40-residue biotinyl peptides, which are released by the trypsin treatment, apparently occur on an exposed portion of the enzyme. This portion of the carboxyl carrier protein apparently serves to place the biotinyl group adjacent to the two substrate sites of the enzyme, one of which is on the peripheral subunit and the other on the central subunit. Thus the carboxyl carrier protein has two functions: one portion holds the 12S and 5S subunits in juxtaposition and the other portion orients the biotinyl group adjacent to the substrate sites so that it may function as a carboxyl carrier between the sites.
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PMID:Isolation of peptides from the carboxyl carrier subunit of transcarboxylase. Role of the non-biotinyl peptide in assembly. 112 90

Inflammatory aneurysms of the abdominal aorta (IAA) comprise 10-15% of all aortic aneurysms (AA) but their aetiology and pathogenesis are obscure. Destruction of mural elastin is a prominent feature of IAA, and both increased elastolysis and decreased inhibition of elastolysis have been implicated. In order to study these factors, we have examined the peripheral blood of three groups of patients; 15 with inflammatory aortic aneurysms (IAA), 61 with simple aortic aneurysms (SAA) and 35 with aorto-iliac occlusive disease (OD). In all cases, alpha-1-anti-trypsin (A-1-AT), alpha-2-macroglobulin (A-2-MG), elastase inhibitory activity (E.I.A.), elastase-anti-trypsin complex, C-reactive protein (CRP), caeruloplasmin (CP) and plasma viscosity were measured. Patients with IAA had a significantly higher plasma viscosity (Mann-Whitney, p less than 0.05), E.I.A. (Mann-Whitney, p less than 0.01) and levels of A-1-AT, CRP, CP and elastase/anti-trypsin complex (Mann-Whitney, all p less than 0.05) than patients in the other two groups. There was no difference in the levels of A-2-MG between any of the groups. This study refutes the theory that reduced inhibition of elastase activity predisposes to the formation of SAA. In patients with IAA, raised marker levels indicate ongoing destruction of elastin, and suggest a difference in pathogenesis between IAA and SAA. The study also suggests that IAA are highly active metabolically, as opposed to the more degenerative SAA.
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PMID:Metabolic activity in inflammatory and non-inflammatory aneurysms of the abdominal aorta. 137 41

The proteasome (multicatalytic protease complex), a high molecular weight protein complex, has been purified from spinach leaves by successive chromatography on DEAE-cellulose, Bio-Gel A-1.5m, DEAE-TOYOPEARL 650C, and DEAE-5PW. The molecular mass was estimated to be 850 kDa by gel filtration. Polyacrylamide gel electrophoresis of the proteasome gave a single protein band under nondenaturing conditions and at least 10 bands in the range of 21-32 kDa in the presence of sodium dodecyl sulfate. By electron microscopy after negative staining with uranyl acetate, the proteasome from spinach appeared as symmetrical ring-shaped particles. The substrate specificity of proteasomes indicates that they contain at least three types of activity, namely, chymotrypsin-like, Staphylococcus aureus V8 protease-like, and trypsin-like activities. The former two activities were enhanced by poly-L-lysine or sodium dodecyl sulfate. Moreover, we examined the immunological reactivities of proteasomes from various eukaryotes. As a result, cross-immunoreactivities of some subunits were observed. These properties of the proteasome are similar to those of proteasomes isolated from various other eukaryotic sources.
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PMID:Purification and initial characterization of the proteasome from the higher plant Spinacia oleracea. 140 Apr 79

Three alternatively spliced forms of the amyloid precursor protein (APP), APP-695, APP-751, and APP-770, were expressed in the baculovirus expression vector system. The recombinant proteins were secreted into the culture medium by infected insect cells, and APP molecules were detected in insect cells and medium 2 days after infection with the recombinant APP-baculoviruses. A partial sequence of the NH2 terminus of the secreted protein revealed identity with the native secreted protein and showed that the signal peptide was recognized and properly cleaved in insect cells. Purified secreted recombinant APP-751 comigrated with protease nexin 2 purified from platelets and fibroblasts. A 15-kDa COOH-terminal fragment of APP was also detected in cells infected with recombinant baculoviruses, suggesting that recombinant APP proteins were cleaved at the COOH-terminal end like native APP protein. Recombinant APP-751 and APP-770 formed complexes with epidermal growth factor-binding protein, whereas APP-695 did not. In addition, recombinant APP-751 and APP-770 inhibited trypsin and chymotrypsin activity, whereas APP-695 did not. Growth of a human fibroblast cell line, A-1, that required APP for complete growth, was restored upon addition of secreted recombinant APP-695 or APP-751. Thus, the appropriately sized, secreted recombinant APP proteins produced in this expression system are biologically active.
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PMID:Expression of active secreted forms of human amyloid beta-protein precursor by recombinant baculovirus-infected insect cells. 194 49

Five intracellular proteases from sporulating cells of Clostridium perfringens type A were identified and three could be separated by DEAE-Sephacel. Two, I-A and I-B, had caseinolytic activity and one, I-C, was only active on N-benzoyl-DL-arginine-p-nitroanilide. I-A and I-B could each be further separated by Sephacryl S-300 into I-A-1 and I-A-2 and I-B-1 and I-B-2, respectively. I-A-1, a chymotrypsin-like enzyme, was the major intracellular protease, constituting 74% of the intracellular caseinolytic activity. In addition to cytoplasmic proteases both trypsin and chymotrypsin-like enzyme activity was associated with the membrane fraction. I-A-1 had a molecular weight of 330,000, with subunits of 120,000 and 138,000. I-A-1 cleaved a 1200 molecular weight peptide from C. perfringens enterotoxin. Early sporulating cell extracts of C. perfringens contained three presumptive enterotoxin precursors, which disappeared following treatment with I-A. Such cells also contained at least 10 spore coat related proteins, only one (51,500 molecular weight) of which was sensitive to I-A-1. The results indicate a possible role for the major intracellular protease in the processing of C. perfringens enterotoxin and a less important role, if any, in spore coat formation.
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PMID:Purification and characterization of intracellular proteases of Clostridium perfringens type A. 202 97


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