Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although the proteinase inhibitor alpha-2-antiplasmin (alpha 2AP) is known to control the activity of plasmin through rapid formation of stable complexes, it also efficiently inactivates chymotrypsin. These interactions are shown to occur at adjacent, overlapping sites so that plasmin attacks the inhibitor at an Arg364-Met365 peptide bond, while chymotrypsin interacts at a Met365-Ser366 sequence one residue downstream. Thus, a naturally occurring plasma serine proteinase inhibitor can have multiple specificities through interactions at adjacent sites. It also illustrates the potential flexibility of the reactive site loop in this class of inhibitors.
 ...
PMID:Alpha-2-antiplasmin: a serpin with two separate but overlapping reactive sites. 245 16

Two new human cell lines, RCM-1 and CoCM-1, have been established from primary colorectal adenocarcinomas. Both cell lines were unique in that the cultures secreted trypsin inhibitors in vitro. The activities of these inhibitors were accumulated in serum-free media of both cell lines over a period of several days. Two inhibitors (PI-1 and PI-2) were isolated from serum-free conditioned medium in which RCM-1 was grown by anion-exchange and gel filtration high-performance liquid chromatography. PI-1 inhibited trypsin and chymotrypsin strongly, and pancreatic elastase weakly. Its molecular weight was about 57 kilodaltons (Kd) as determined by gel filtration chromatography. It cross-reacted with the antiserum elicited against human alpha 1-antitrypsin in double immunodiffusion. PI-1 corresponding to alpha 1-antitrypsin was also demonstrated immunohistochemically in both cell lines. PI-2 inhibited trypsin strongly, and chymotrypsin, kallikrein and plasmin weakly. It had higher molecular weight (200-300 Kd) than that of PI-1, and did not cross-react with antisera against human alpha 1-antitrypsin, alpha 2-macroglobulin, alpha 1-antichymotrypsin, alpha 2-plasmin inhibitor, inter-alpha-trypsin inhibitor and urinary trypsin inhibitor. RCM-1 and CoCM-1 are the first colorectal adenocarcinoma cell lines that secrete functionally active trypsin inhibitors, including alpha 1-antitrypsin in vitro, and are useful for the study of tumor-cell derived proteinase inhibitors.
 ...
PMID:New human colorectal carcinoma cell lines that secrete proteinase inhibitors in vitro. 257 Apr 82

We have isolated three cDNA clones for human alpha 2-plasmin inhibitor (alpha 2-PI). Two clones are from human hepatoma cell line, Hep G2, and cover the entire protein coding region plus the 3'-flanking region up to the poly(A) sequence, and the other clone is from human liver and contains the carboxyl-terminal half. The total length of the cDNAs is 2.29 kb, corresponding to more than 95% of the full-length mRNA. alpha 2-PI seems to consist of 452 amino acid residues plus 39 amino acid residues for the signal peptide. The amino acid sequence shows 23 to 28% homology to those of five other protease inhibitors, plasminogen activator inhibitor (PAI), protein C inhibitor (PCI), alpha 1-antitrypsin (alpha 1-AT), antithrombin III (AT III), and alpha 1-antichymotrypsin (alpha 1-AC). alpha 2-PI seems to be the most distantly related among these inhibitors. Comparison of the phylogenetic trees of proteases and their inhibitors indicates that four proteases, namely elastase (or trypsin), chymotrypsin, plasminogen activator, and thrombin, may have evolved concurrently with the corresponding inhibitors. However, alpha 2-PI and PCI seem to have evolved asynchronously from their substrates. The data suggest that alpha 2-PI may originally have inhibited some protease other than plasmin, and protein C may have had an inhibitor different from the present one early in its evolutionary history.
 ...
PMID:Structure of human alpha 2-plasmin inhibitor deduced from the cDNA sequence. 283 Feb 48

An acid-stable protease inhibitor (AS-PI) has been previously demonstrated in ascitic fluid from patients with ovarian carcinoma. In this study, the AS-PI was further purified using DEAE-cellulose and isoelectric focusing (IEF), and a partial characterization was undertaken. On DEAE-cellulose ion-exchange column chromatography, AS-PI activity was observed in both adsorbed and non-adsorbed fractions. The former represented the main AS-PI peak. By IEF, the respective pI values were 1.6 and 4.5. By gel filtration, the molecular weight of the main (adsorbed fraction) AS-PI was 78 000. This AS-PI strongly inhibited trypsin and to a lesser extent chymotrypsin, but exerted no inhibitory effect on plasmin. It slightly inhibited SH proteases such as papain and ficin. Immunologically, AS-PI was distinct from alpha 1-antitrypsin, alpha 1-antichymotrypsin, inter-alpha-trypsin inhibitor, antithrombin III, C1-inactivator, alpha 2-macroglobulin and alpha 2-plasmin inhibitor. The main AS-PI reacted with and was neutralized by antiurinary trypsin inhibitor serum, and on immunoelectrophoresis, had a mobility slightly cathodal to serum albumin.
 ...
PMID:Further purification and characterization of acid-stable protease inhibitor from ascites of an ovarian carcinoma patient. 643 8