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)

Low salt extracts from homogenates of bovine cardiac muscle contain two protease inhibitors, one specific for the calcium-activated protease from this tissue and the other for trypsin and chymotrypsin, but no other serine proteases, including plasmin, thrombin, and subtilisin. The former, which can be separated from the protease by chromatography on DEAE-cellulose, is a protein with a molecular weight of 270,000. Its action is not based on the sequestering of calcium, and it is present in large excess over the amount of calcium-activated protease in this tissue. The trypsin inhibitor, which has a molecular weight of 70,000, is estimated to be present at approximately 300 microgram/g, wet weight, of tissue. The identification of inhibitors such as these in the cytoplasm may explain why nonlysosomal proteolytic activity has been thought to be insignificant in the overall turnover of intracellular protein and suggests that a re-evaluation of this possibility is necessary.
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PMID:Identification of two protease inhibitors from bovine cardiac muscle. 68 25

Synthetic procedures have been developed for the preparation of peptides of arginine chloromethyl ketone and applied in the preparation of affinity labels which correspond to the -Pro-Phe-Arg- C terminus of bradykinin, a physiological cleavage site of kallikrein in kininogen. Two such reagents, Ala-Phe-ArgCH2C1 and Pro-Phe-ArgCH2C1, proved to be highly effective as well as selective affinity labels for human plasma kallikrein. For example, Pro-Phe-ArgCH2C1 inactivates plasma kallikrein 50% in 24 min at a concentration of 2 x 10(-8)M, while other trypsin-like proteases are less susceptible in inactivation than kallikrein, differing by a factor of 48 for plasmin and factors of 10(2)-10(5) for factor Xa, thrombin, and urokinase. The affinity of human plasma kallikrein for Ala-Phe-ArgCH2C1 (Ki = 0.078 micron) is about 60 times that for Ala-Phe-LysCH2C1(Ki = 4.9 micron), whereas human plasmin exhibits about the same affinity for the former affinity label (Ki = 1.3 micron) as for the latter (Ki = 0.83 micron). The rate constants for the irreversible step of the affinity labeling reaction, k2, are similar for affinity labels tested with the individual proteases: 0.35 min-1 for plasma kallikrein and 0.18 min-1 for plasmin.
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PMID:Synthesis of peptides of arginine chloromethyl ketone. Selective inactivation of human plasma kallikrein. 72 86

We have examined the ability of 5 tumour cell types to attach to plastic flasks in medium containing either 10% foetal calf serum or 10% normal human serum and compared this ability with cell-associated caseinolytic activity. The cell types used included fibrosarcoma cells which were obtained from a methylcholanthrene-induced tumour in a C57 BL/6 mouse, the SV40-transformed 3T3 (BALB/c) cells, the Walker carcinosarcoma cells and 2 lines of HeLa cells. All 5 cell types attached to the flasks and spread out efficiently in medium containing 10% foetal calf serum. The walker carcinosarcoma cells and the 2 lines of HeLa cells also attached efficiently in medium containing 10% normal human serum and grew into monolayers in this medium. These 3 cell types had no detectable caseinolytic activity. The fibrosarcoma cells and the SV40-transformed 3T3 (BALB/c) cells did not attach in normal human serum-containing medium. These 2 cell types had readily detected caseinolytic activity. Normal human serum and foetal calf serum were compared for levels of protease-inhibitor activity. Human serum was found to have less activity than foetal calf serum against both trypsin and plasmin as well as the cell-associated caseinolytic activity. The low level of protease inhibitor activity in normal human serum may contribute to the inability of this serum to support the attachment of cells with detectable protease activity because the addition of protease inhibitors such as soybean trypsin inhibitor, lima bean trypsin inhibitor and bovine pancreas trypsin inhibitor to normal human serum dramatically enhanced cell attachment. In contrast to this, the addition of E-amino-n-caproic acid to normal human serum and the removal of plasminogen from normal human serum did not enhance its capacity to support cell attachment.
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PMID:Comparison of cell attachment and caseinolytic activities of five tumour cell types. 74 34

The lectin present in the mucus of the snail Arion empiricorum was isolated by ion exchange chromatography. Purity was demonstrated by immunelectrophoretic analysis, immunization studies, and polyacrylamide gel electrophoresis. With the latter we found a molecular weight of 43,000. Hemagglutination inhibition studies revealed that carbohydrates play a minor role in the agglutination reaction of A. empiricorum lectin. Stronger inhibition could be achieved with human serum and the serum of several animal species. These findings were clarified by the demonstration that some serum proteins were precipitated by A. empiricorum lectin. Besides its agglutinating and precipitating properties the purified A. empiricorum lectin possesses proteinase-inhibiting properties, as demonstrated by the inhibition of casein-digestion by trypsin and plasmin.
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PMID:Isolation and new biological properties of Arion empiricorum lectin. 76 Aug 14

Monomer proteoglycan was isolated from porcine ovarian follicular fluid by isopycnic CsCl centrifugation in the presence of 4 M guanidine HCl and protease inhibitors. The elution profile of the D1 preparation on Sepharose 2B was similar to that of monomer proteoglycan from bovine nasal cartilage, indicating a similar molecular size. Follicular fluid proteoglycans consist of about 20% protein, 50% dermatan sulfate, and 20% oligosaccharides rich in sialic acid, galactose, mannose, glucosamine, and galactosamine. The amino acid composition of this proteoglycan is significantly different from that of cartilage proteoglycans, with a higher proportion of aspartic acid, threonine, and lysine, and lower amounts of proline and glycine. Alkali-released dermatan sulfate chains are larger on Sepharose 6B (average Mr = 56,000) than chondroitin sulfate chains from cartilage proteoglycans (average Mr = 25,000), and iduronic acid accounts for 9% of total hexuronic acid. Disaccharide units released by chondroitinase ABC consists of 67% 4-sulfated, 22% 6-sulfated, 5% non-sulfated, and 5% disulfated disaccharides. After treatment with 0.05 M NaOH, 1 M NaBH4 at 45 degrees C for 24 h, two major sialic acid-containing oligosaccharides were observed on Sephadex G-25, corresponding to penta- and hexasaccharides. The pentasaccharide contained sialic acid, galactose, glucosamine, and galactosamine in the proportions 1:2:1:1. The galactosamine is O-glycosidically linked to the protein core. This oligosaccharide accounts for approximately 77% of all the sialic acid in the follicular fluid proteoglycans. The hexasaccharide fraction contained sialic acid, galactose, mannose, and glucosamine in the proportions 1:2:1:2. It also contained a small amount of fucose and galactosamine. The linkage of these oligosaccharides to the protein core remains to be determined. The follicular fluid proteoglycans, unlike those from cartilage, do not interact with hyaluronic acid. Digestion with trypsin, chymotrypsin, or plasmin released dermatan sulfate-peptides nearly as small as those released by papain or alkali; in contrast, cartilage proteoglycans were resistant to plasmin and released peptides containing an average of more than four chondroitin sulfate chains after trypsin or chymotrypsin digestion.
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PMID:Isolation and characterization of proteoglycans from porcine ovarian follicular fluid. 76

Contamination of werum by certain gram-negative bacteria has been shown to spoil the serum for measurement of trypsin inhibitory capacity (STIC) or for antitrypsin phenotyping. Such sera develop intense fibrinolytic activity when the STIC has dropped to itsminimal level, but antitrypsin concentration as measured by radial immunodiffusion remainsconstant. Cultures of ENTEROBACTER, Klebsiella, Bacillus subtilis, and Pseudomonas species were shown to have this capability, but production of the fibrinolytic enzyme by the bacteria was most proficient in the presence of human serum. The enzyme is believed to be of bacterial origin because of its lack of esterase activity, and because activation of serum plasmin by streptokinase did not affect the STIC. Care mustbe taken to avoid bacterial contamination of blood that is to be submitted for an STICassay and/or antitrypsin phenotyping. Serum should be prepared quickly, frozen soon,and stored and transported in a frozen state.
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PMID:Interference with alpha-antitrypsin studues in stored serum by presumed bacterial proteases. 80 60

Guinea pig peritoneal macrophages were demonstrated to bind selectively soluble 125I-fibrin and fibrin/fibrinogen complexes as compared with fibrinogen, fibrinogen degradation products, and fibrin degradation products. Cellular uptake was considered to be surface receptor binding on the basis of removal of bound 125I-fibrin by trypsin and because uptake occurred in the presence of metabolic inhibitors. 125I-fibrin uptake could be blocked by nonradioactive fibrin but not by IgG or immune complexes. Binding was uneffected by prior treatment with plasmin or trypsin but was calcium dependent. Only limited reversibility of binding could be demonstrated after prolonged incubation. Scatchard plots permitted an estimate of the number of bound molecules. At saturation 6.92 X 10(6) 125I-fibrin molecules were bound per cell. Similar binding of fibrin was noted in polymorphonuclear leukocytes, but not lymphocytes or fibroblasts. Soluble fibrin binding may be a host defense mechanism whereby the reticuloendothelial system can remove fibrin from the blood before the development of microthrombi.
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PMID:Specific binding of soluble fibrin to macrophages. 83 Jul 91

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

Simultaneous to the liberation of the acid stable trypsin-plasmin-inhibitor from the inter-alpha-trypsininhibitor in vivo, acid labile degradation products are set free. The main product can be estimated by immunological methods. This product is not excreted by the kidney in contrast to the acid stable inhibitor. The product accumulates in serum in different diseases. An increased concentration of this product indicates also an increased turn-over of the inter-alpha-trypsin inhibitor in the case when the concentraton of the intact inter-alpha-trypsin inhibitor or of the filtrable derivative are within normal range.
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PMID:[About degradation products of the inter-alpha-trypsin inhibitor in serum. II. Acid label derivatives of the inter-alpha-trypsin inhibitor (author's transl)]. 85 85

D was purified to homogeneity from outdated human plasma by successive chromatography on Bio Rex 70, Sephadex G-200, Bio Rex 70, and Sephadex G-75. Column fractions were monitored for D activity by a hemolytic diffusion plate assay. The overall yield was approximately 4% by activity. A m.w. of 22,900 daltons was established by sedimentation equilibrium. Amino acid analyses have been obtained and Isoleucine has been determined as the NH2-terminus. Incubation of D with purified B and CoVF in the presence of Mg++ resulted in cleavage of B, as judged by SDS-polyacrylamide gel electrophoresis and immunoelectrophoresis. D hydrolyzed certain synthetic amino acid esters of arginine, lysine, and tyrosine. Benzoyl-L-arginine methyl esters (BAME) was the most sensitive substrate for D among those tested. The substrate profile of D was dinstinct when compared to that of CIs, CIr, plasmin, urokinase, and trypsin. Both the enzymatic and hemolytic activity of D were irreversibly inhibited by treatment with 10 mM DFP as well as by reduction and alkylation.
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PMID:Human factor D of the alternative complement pathway: purification and characterization. 87 24


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