Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.86 (clotting enzyme)
 176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A pro-clotting enzyme capable of causing the gelation of clottable proteins in Limulus polyphemus (horseshoe crab) has been purified to apparent homogeneity as judged by sodium dodecyl sulfate-gel electrophoresis. The activation of the pro-clotting enzyme depended on the presence of both Ca+ and endotoxin. It contained gamma-carboxyglutamic acids and gave a single NH2-terminal lysine. The enzyme was inhibited by diisopropyl fluorophosphate, phenylmethylsulfonyl fluoride, and soy bean trypsin inhibitor, indicating that it is a serine protease. The molecular weight of the proclotting enzyme was determined to be at least 150,000 by sodium dodecyl sulfate-gel electrophoresis under reducing and denaturing conditions. The protein appears to consist of a single peptide chain, since exposure of the reduced and carboxymethylated enzyme to 6 M guanidine hydrochloride failed to dissociate it into any subunits.
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PMID:Studies on Limulus amoebocyte lysate. Isolation of pro-clotting enzyme. 32 51

A low molecular weight protein protease inhibitor was purified from Japanese horseshoe crab (Tachypleus tridentatus) hemocytes. It consisted of a single polypeptide with a total of 61 amino acid residues. This protease inhibitor inhibited stoichiometrically the amidase activity of trypsin (Ki = 4.60 X 10(-10) M), and also had inhibitory effects on alpha-chymotrypsin (Ki = 5.54 X 10(-9) M), elastase (Ki = 7.20 X 10(-8) M), plasmin, and plasma kallikrein. However, it had no effect on T. tridentatus clotting enzyme and factor C, mammalian blood coagulation factors (activated protein C, factor Xa and alpha-thrombin), papain, and thermolysin. The complete amino acid sequence of this inhibitor was determined and its sequence was compared with those of bovine pancreatic trypsin inhibitor (BPTI) and other Kunitz-type inhibitors. It was found that the amino acid sequence of this inhibitor has a high homology of 47 and 43% with those of sea anemone inhibitor 5-II and BPTI, respectively. Thus, this protease inhibitor appeared to be one of the typical Kunitz-type protease inhibitors.
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PMID:Purification and amino acid sequence of Kunitz-type protease inhibitor found in the hemocytes of horseshoe crab (Tachypleus tridentatus). 330 64

A clotting enzyme, associated with the endotoxin-mediated activation of the cellularly based coagulation system of the American horseshoe crab (Limulus polyphemus), was considerably purified by a modification of the method employed to purify the corresponding enzyme from the Japanese horseshoe crab (Tachypleus tridentatus) (Nakamura, et al., 1982). This enzyme was inhibited by DFP, benzamidine, p-aminobenzamidine, antithrombin III, soybean trypsin inhibitor, and antipain, suggesting that it is a trypsin-type serine protease. The enzyme demonstrated amidolytic activity to Ac-Ile-Glu-Gly-Arg-pNA (S-2423) and related synthetic substrates (S-2222, S-2422, S-2337, and Boc-Leu-Gly-Arg-pNA) but not to other substrates (S-2160, S-2238, S-2251, S-2444, S-2266, and S-2302), indicating specificity similar to mammalian blood coagulation Factor Xa. These properties of the Limulus enzyme were identical with those of the corresponding Tachypleus enzyme. The structure and function of the enzymes in these two species probably have been highly conserved during the past few hundred million years of their evolution.
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PMID:Properties of the clotting enzyme responsible for endotoxin-mediated Limulus coagulation. 637 72

Moulting fluid of pharate adult tobacco hornworm moths, Manduca sexta, contains a novel cuticle-degrading proteinase, designated as MFP-1. The enzyme has been purified using heparin affinity chromatography and partially characterized. Before purification MFP-1 is associated with a large complex having an apparent native molecular mass > 669 kDa. After purification MFP-1 has a molecular mass of 41 kDa. The pI of the enzyme is 5.54. MFP-1 can be classified as generally trypsin-like on the basis of its substrate specificity and inhibition by soybean trypsin inhibitor. The enzyme's preferred substrate, Tos-Gly-Pro-Arg-pNA, its inhibition by hirudin, and its affinity for heparin, all indicate that MFP-1 has some characteristics in common with the vertebrate blood-clotting enzyme thrombin. MFP-1 is probably a serine protease, since it is inhibited by both DFP and PMSF (specific inhibitors of serine proteinases). However, the enzyme was also inhibited by a number of agents that affect cysteine proteinases. Purified MFP-1 degrades Manduca cuticle in vitro. We suggest that the enzyme may act as the first step in the degradation of the cuticle during the moulting process.
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PMID:A cuticle-degrading proteinase from the moulting fluid of the tobacco hornworm, Manduca sexta. 835 21

Snake venom serine proteinases, which belong to the subfamily of trypsin-like serine proteinases, exhibit a high degree of sequence identity (60-66%). Their stringent macromolecular substrate specificity contrasts with that of the less specific enzyme trypsin. One of them, the plasminogen activator from Trimeresurus stejnegeri venom (TSV-PA), which shares 63% sequence identity with batroxobin, a fibrinogen clotting enzyme from Bothrops atrox venom, specifically activates plasminogen to plasmin like tissue-type plasminogen activator (t-PA), even though it exhibits only 23% sequence identity with t-PA. This study shows that TSV-PA, t-PA, and batroxobin are quite different in their specificity toward small chromogenic substrates, TSV-PA being less selective than t-PA, and batroxobin not being efficient at all. The specificity of TSV-PA, with respect to t-PA and batroxobin, was investigated further by site-directed mutagenesis in the 189-195 segment, which forms the basement of the S(1) pocket of TSV-PA and presents a His at position 192 and a unique Phe at position 193. This study demonstrates that Phe(193) plays a more significant role than His(192) in determining substrate specificity and inhibition resistance. Interestingly, the TSV-PA variant F193G possesses a 8-9-fold increased activity for plasminogen and becomes sensitive to bovine pancreatic trypsin inhibitor.
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PMID:The contribution of residues 192 and 193 to the specificity of snake venom serine proteinases. 1063 81