Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 427-fold purification of rat urinary kallikrein (RUK) was achieved in three steps involving chromatography on columns of DEAE-Sepharose CL-6B, gel filtration on Sephadex G-100 and affinity chromatography on a column of benzamidine-Sepharose. Purified enzyme showed a single band on SDS-PAGE with an estimated molecular weight of 43,000. The amino-terminal sequences of the first 25 residues of RUK resemble the reported sequence for true kallikrein and share 80% identity with rat submandibular gland (RSMG) kallikrein-like serine protease. The RUK is highly reactive towards kallikrein substrates Bz-pro-phe-arg-pNA and DL-val-leu-arg-pNA, and plasmin substrate D-val-leu-lys-pNA. RSMG enzyme is more reactive towards Bz-val-gly-arg-pNA and tosyl-gly-pro-arg-pNA, preferential chromogenic substrates for trypsin-like proteases and thrombin, respectively. Both leupeptin and aprotinin inhibit RUK strongly, but soy bean trypsin inhibitor has no effect on this enzyme. RSMG enzyme is poorly inhibited by any of these inhibitors. The data suggest that although both enzymes are members of tissue kallikrein multigene family, urinary enzyme is a true kallikrein and RSMG enzyme is a kallikrein-like serine protease with different substrate specificity.
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PMID:Purification of rat urinary kallikrein: comparative studies with rat submandibular gland kallikrein-like serine protease. 128 50

Proteinase species secreted by 10 human gastric carcinoma cell lines were analyzed by gelatin zymography and immunoblotting. These cell lines were classified into the following three groups with respect to proteinase secretion: cell lines secreting mainly gelatinases A and/or B; those secreting multiple types of serine proteinases; and those scarcely secreting these enzymes. Two cell lines of the second group, STKM-1 and MKN28, hardly secreted metalloproteinases but secreted the following four types of serine proteinases: (a) two trypsin-like enzymes (M(r) 26,000 and 24,000 in proenzyme forms); (b) a tissue kallikrein-like enzyme (M(r) 150,000 in a complex form); (c) a plasmin-like enzyme (M(r) 70,000); and (d) a plasminogen activator (urokinase-type, M(r) 57,000, from STKM-1 and tissue-type, M(r) 70,000, from MKN28). The M(r) 70,000 plasmin-like enzyme was also detected at lower levels in the conditioned media of four other cell lines (MKN1, MKN45, NUGC-3, and KATO III). The M(r) 24,000 proenzyme of the trypsin-like enzyme was purified from the serum-free conditioned medium of STKM-1. The proenzyme was activated by enterokinase treatment or autolytically by incubation at neutral pH, decreasing its apparent molecular weight from 24,000 to 23,000 on nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The activated enzyme extensively degraded fibronectin, laminin, and gelatins and to lesser extents type I, III, IV, and V collagens at 30 degrees C. These results suggest that the matrix serine proteinases may play a major role in the matrix degradation by some kinds of human cancer cells.
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PMID:Multiple secretion of matrix serine proteinases by human gastric carcinoma cell lines. 138 87

Besides guanidino compounds and amines structurally related to arginine and lysine, compounds with other cationic groups are inhibitors of trypsin-like serine proteinases. Particularly aromatic ring structures with an amidino moiety have high affinity for these enzymes. In most cases ordinary benzamidine derivatives are no selective inhibitors, however, among derivatives of N alpha-arylsulfonyl-omega-amidinophenyl-alpha-amino-alkylcarboxylic acids selective competitive inhibitors of several enzymes were found. Amides of phenyl-alpha-aminobutyric acid containing an amidino moiety are inhibitors of plasma kallikrein. The p-amidinoanilide of 2-tosylamino-4-phenylbutyric acid inhibits selectively plasma kallikrein with a Ki of 0.70 mumol/l. In contrast, potent and selective inhibitors of glandular kallikrein were hardly found among benzamidines.
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PMID:Inhibition of glandular and plasma kallikrein by benzamidine derivatives. 146 70

A number of ligands for the selective purification by affinity chromatography of the trypsin-like protease, porcine pancreatic kallikrein, were designed de novo by computer-aided molecular design. The ligands were designed to mimic the side-chains of a number of arginyl dipeptides and included a benzamidine moiety substituted on a triazine ring. The ligands displayed inhibitory activities against pancreatic kallikrein which mirrored the specificity constants of the dipeptides they were designed to mimic. The ligand with the highest affinity for the enzyme, an analogue of a Phe-Arg dipeptide, when immobilized to Sepharose CL-4B via a hexamethylene spacer arm, purified pancreatic kallikrein 110-fold in one step from a crude pancreatic acetone extract.
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PMID:Design of novel affinity adsorbents for the purification of trypsin-like proteases. 147 81

Two trypsin inhibitors (TI-1, TI-2) were isolated from guinea pig plasma and purified to homogeneity. In amino-acid composition as well as molecular masses, TI-1 (Mr 58,000) and TI-2 (Mr 57,000) are similar to each other and to human and mouse alpha 1-proteinase inhibitors, and mouse con-trapsin. The two inhibitors form equimolar complexes with proteinases. The effectiveness of the inhibitors was characterized by association rate constants under second-order rate conditions. The inhibitory action of TI-1 was rapid for bovine trypsin, porcine pancreatic elastase and guinea pig plasma kallikrein, but slow for bovine thrombin and guinea pig plasmin and not detectable for bovine chymotrypsin and porcine pancreatic kallikrein. The inhibitory action of TI-2 was rapid for trypsin and chymotrypsin, but slow for guinea pig plasma kallikrein and not detectable for other proteinases. These results show that TI-1 and TI-2 are physicochemically similar but functionally distinct from each other and from human alpha 1-proteinase inhibitor that inhibits trypsin, chymotrypsin and elastase.
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PMID:Guinea pig plasma trypsin inhibitors. Purification and characterization of two functionally distinct proteinase inhibitors. 153 92

The posterior stomach was isolated from each male Donryu rat and separated into two parts: the tunicae mucosa and submucosa and the tunicae muscularis and serosa. Active and inactive tissue kallikrein were measured using sandwich type enzyme linked immunosorbent assay (s-ELISA) and H-Pro-Phe-Arg-MCA to complement each other. Inactive tissue kallikrein was determined (1) by measuring total tissue kallikrein and active tissue kallikrein in trypsin-treated samples and trypsin-nontreated ones, respectively; and (2) by subtracting active tissue kallikrein from total tissue kallikrein. Although tissue kallikrein was not demonstrable in the tunicae muscularis and serosa, inactive tissue kallikrein in the tunicae mucosa and submucosa reached 79.6% with s-ELISA and 99.1% with H-Pro-Phe-Arg-MCA. Water-immersion stress significantly decreased total tissue kallikrein at Stage IV of ulcers compared with the control value (p less than 0.001 in both measuring methods). Immunohistochemical staining was made using the avidin-biotin-horseradish peroxidase complex method. Tissue kallikrein was proved to be diffusely present as the inactive type within the epithelial cells of the pits in the gastric mucosa of the normal rats. With the progress of ulcers, however, it disappeared from the cells and appeared in the intercellular space. At Stage IV, it began to disappear even from the intercellular space. Based on the previously proposed process of tissue kallikrein release into blood in man, a possible interpretation of the above findings is that inactive tissue kallikrein may serve to maintain the gastric mucosa in a normal state; and that it may be transformed into the active type with ulceration and eliminated in a form of complex with some protease inhibitor in the course of aggravation.
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PMID:[Bio- and histochemical changes of tissue kallikrein in the rat stomach after water immersion-induced gastric ulcer]. 159 73

FUT-187, a newly synthesized compound, was studied on its inhibitory activities mainly on proteolytic enzymes, in comparison with those of FUT-175 and FOY-305, known serine protease inhibitors. FUT-187, as well as FUT-175 and FOY-305, had selective inhibitory activities on serine proteases including Clr, Cls, kallikrein, trypsin, plasmin and thrombin; its activities on these enzymes except Clr and pancreatic kallikrein were relatively lower than those of FUT-175 and FOY-305. Further studies were conducted focusing on complement-mediated reactions. In spite of its lower activities against Clr and Cls, inhibitions by FUT-187 on the complement-mediated hemolysis in vitro and in vivo were only a little weaker than or equivalent to that of FUT-175. FOY-305 was ineffective in these tests. Forssman shock in guinea pigs is known to be initiated by the activation of the complement system. The protective effect of intravenous or oral FUT-187 against this shock was definitely superior to that of FUT-175. Furthermore, FUT-187 inhibited changes accompanied with Forssman shock, such as increase in lung weight, the decrease in platelet counts and CH50, and histopathological changes. These results suggested that FUT-187 should be a more potent oral therapeutic agent than FUT-175 for various inflammatory diseases attributed to the excessive activation of the complement system followed by platelet aggregation.
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PMID:Pharmacological studies on 6-amidino-2-naphthyl[4-(4,5-dihydro-1H-imidazol-2-yl)amino] benzoate dimethane sulfonate (FUT-187). I: Inhibitory activities on various kinds of enzymes in vitro and anticomplement activity in vivo. 168 82

Prostate-specific antigen (PSA) is one of the three most abundant prostatic-secreted proteins in human semen. It is a serine proteinase that, in its primary structure, manifests extensive similarities with that of the Arg-restricted glandular kallikrein-like proteinases. When isolated from semen by the addition of chromatography on aprotinin-Sepharose to a previously described procedure, PSA displayed chymotrypsin-like activity and cleaved semenogelin and the semenogelin-related proteins in a rapid and characteristic pattern, but had no trypsin-like activity. About one third of the purified protein was found to be enzymatically inactive, due to cleavage carboxy-terminal of Lys145. Active PSA formed SDS-stable complexes with alpha 1-antichymotrypsin, alpha 2-macroglobulin-analogue pregnancy zone protein. PSA formed inhibitory complexes with alpha 1-antichymotrypsin at a molar ratio of 1:1, a reaction in which PSA cleaved the inhibitor in a position identical to that reported from the reaction between chymotrypsin and alpha 1-antichymotrypsin. The formation of stable complexes between PSA and alpha 1-antichymotrypsin occurred at a much slower rate than that between chymotrypsin and alpha 1-antichymotrypsin, and at a similar or slightly slower rate than that between PSA and alpha 2-macroglobulin. When added to normal blood plasma in vitro, active PSA formed stable complexes both with alpha 2-macroglobulin and alpha 1-antichymotrypsin. This complex formation may be a crucial determinant of the turnover of active PSA in intercellular fluid or blood plasma in vivo.
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PMID:Enzymatic activity of prostate-specific antigen and its reactions with extracellular serine proteinase inhibitors. 170 14

PSA is a 34-kd 240-amino acid glycoprotein produced by the prostatic epithelial cells. It is a member of the glandular kallikrein gene family and has a high sequence homology with human glandular kallikrein (hGK-1). PSA is a serine protease and has chymotrypsin-, trypsin-, and esterase-like activities. It is secreted into the seminal fluid where it degrades two seminal vesicle proteins that are important components of the semen coagulum, thus playing an important role in semen liquefaction. The production of PSA protein appears to be under the control of circulating androgens acting through the androgen receptor. Therefore, the significance of a low serum PSA value in a patient who has undergone previous antiandrogen therapy may not be the same as that for a patient who has not received endocrine treatment.
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PMID:Prostate-specific antigen and prostatic acid phosphatase: biomolecular and physiologic characteristics. 171 6

The substitution of amino acids in the reactive site of aprotinin, a bovine serine proteinase inhibitor with potent activity against trypsin, plasmin and tissue kallikrein, led to a change in specificity of the inhibitor. Twelve new aprotinin variants prepared by recombinant DNA technology and expressed in Escherichia coli clearly demonstrated that the neighbouring groups of the P1 residue, in particular P'2, contribute to the specificity of the inhibitor, while earlier investigations on semisynthetically prepared variants revealed the importance of the P1 residue in dominating the inhibitory specificity. Recombinant aprotinin variants which act specifically against chymotrypsin-like proteinases, were obtained by substitution of the amino acids in position P1 and P'2 by hydrophobic amino acids like phenylalanine, tyrosine and leucine. Some of these variants, particularly those with phenylalanine or leucine substitutions, were also found to exhibit inhibitory activity against cathepsin G with an equilibrium constant of dissociation Ki of 10(-8) M. Inhibitory specificity against cathepsin G was not found in any semisynthetic variant prepared earlier.
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PMID:Recombinant aprotinin homologue with new inhibitory specificity for cathepsin G. 171 53


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