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

The interaction of novel series of synthetic inhibitors with various serine proteases (leukocyte elastase, thrombin, cathepsin G, chymotrypsin, plasminogen activators and plasmin) and an aspartic protease (HIV-1 protease) were studied. Various aspects were analyzed: mechanism of action, structure-activity relationships, and in some cases, molecular modelling and biological evaluation. Functionalized cyclopeptides and N-aryl azetidin-2-ones behaved as suicide substrates acting specifically on trypsin-like proteases (thrombin or urokinase) and elastases, respectively. Novel hydrazinopeptides acted as reversible inhibitors of elastases. Coumarin derivatives inactivated very efficiently chymotrypsin-like proteases (k(inact)/K(I) = 760,000 M(-1) .s(-1)). Inhibitors of HIV-1 protease acting either as inactivators or dimerization inhibitors are under investigation. The inhibitors described above are useful for elucidating the biological roles of the target enzymes and constitute potential drugs.
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PMID:[Synthetic inhibitors targeting serine and aspartic acid proteases]. 877 49

A serine proteinase inhibitor (ovomucoid) has been isolated from duck egg white. The duck ovomucoid effectively inhibited HLE, PPE, chymotrypsin, and HCG in a 1:1 molar ratio, and trypsin in a 1:2 molar ratio. Inhibition of human plasmin and porcine pancreatic kallikrein was not observed. The ovomucoid shows equilibrium dissociation constants of 0.002; 2.4; 2.2; 6.1; and 18.0 nM for HLE, PPE, chymotrypsin, trypsin, and HCG, respectively. The molecule of inhibitor can simultaneously bind two trypsin molecules and one molecule of elastase (or chymotrypsin).
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PMID:A novel human leukocyte elastase inhibitor from duck egg white. 879 82

Barley serpin BSZx is a potent inhibitor of trypsin and chymotrypsin at overlapping reactive sites (Dahl, S.W., Rasmussen, S.K. and Hejgaard, J. (1996) J. Biol. Chem., in press). We have now investigated the interactions of BSZx with a range of serine proteinases from human plasma, pancreas and leukocytes, a fungal trypsin and three subtilisins. Thrombin, plasma kallikrein, factor VIIa/tissue factor and factor Xa were inhibited by BSZx at heparin independent association rates (k(ass)) of 4.5 X 10(3)-1.3 x 10(5) M(-1) s(-1) at 22 degrees C. Only factor Xa turned a significant fraction of BSZx over as substrate. Complexes of these proteinase with BSZx resisted boiling in SDS, and amino acid sequencing showed that cleavage in the reactive center loop only occurred after P1 Arg. Activated protein C and leukocyte elastase were slowly inhibited by BSZx (k(ass)=1-2 x 10(2) M(-1) s(-1)) whereas factor XIIa, urokinase and tissue type plasminogen activator, plasmin and pancreas kallikrein and elastase were not or only weakly affected. The inhibition pattern with mammalian proteinases reveal a specificity of BSZx similar to that of antithrombin III. Trypsin from Fusarium was not inhibited while interaction with subtilisin Carlsberg and Novo was rapid but most BSZx was cleaved as a substrate. Identification of a monoclonal antibody specific for native BSZx indicate that complex formation and loop cleavage result in similar conformational changes.
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PMID:Inhibition of coagulation factors by recombinant barley serpin BSZx. 884 56

Three protease inhibitors (BWI-1, BWI-2 and BWI-4) from buckwheat seeds were purified to homogeneity and characterized. Their molecular masses were 7.7-9.2 kDa according to gel-filtration and mass spectrometry. Amino acid analysis revealed a high content of glutamic acid and valine and a low content of isoleucine, aromatic and sulfur-containing amino acids. Data illustrating the temperature and the pH stability of the inhibitors are presented. Each of the inhibitors formed a inhibitor complex with trypsin in a molar ratio 1:1 and contained an Arg residue at the reactive site. In addition to trypsin, BWI-1 and BWI-2 inhibited chymotrypsin, however, less effectively. None of the isolated inhibitors suppressed activity of papain, leukocyte elastase, pepsin and subtilisin.
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PMID:Isolation and properties of anionic protease inhibitors from buckwheat seeds. 888 86

The P1 or primary specificity residue of standard mechanism canonical protein inhibitors of serine proteinases, inserts into the S1 primary specificity cavity of the cognate enzyme upon enzyme-inhibitor complex formation. Both natural evolution and protein engineering often change the P1 residue to greatly alter the specificity and the binding strength. To systematize such results we have obtained all 20 coded P1 variants of one such inhibitor, turkey ovomucoid third domain, by recombinant DNA technology. The variants were extensively characterized. The association equilibrium constants were measured at pH 8.30, 21 (+/-2) degrees C, for interaction of these variants with six well characterized serine proteinases with hydrophobic S1, cavities. The enzyme names are followed by the best, worst and most specific coded residue for each. Bovine chymotrypsin A alpha (Tyr, Pro, Trp), porcine pancreatic elastase (Leu/Ala, Arg, Ala), subtilisin Carlsberg (Cys, Pro, Glu), Streptomyces griseus proteinase A (Cys, Pro, Leu) and B (Cys, Pro, Lys) and human leukocyte elastase (Ile, Asp, Ile). The data set was merged with Ka values for five non-coded variants at P1 of turkey ovomucoid third domain obtained in our laboratory by enzymatic semisynthesis. The ratios of the highest to the lowest Ka for each of the six enzymes range from 10(6) to 10(8). The dominant force for binding to these pockets is the hydrophobic interaction. Excess steric bulk (too large for the pocket), awkward shape (Pro, Val and Ile), polarity (Ser) oppose interaction. Ionic charges, especially negative charges on Glu- and Asp- are strongly unfavorable. The Pearson pro duct moment correlations for all the 15 enzyme pairs were calculated. We suggest that these may serve as a quantitative description of the specificity of the enzymes at P1. The sets of Streptomyces griseus proteinases A and B and of the two elastases are strongly positively correlated. Strikingly, chymotrypsin and pancreatic elastase are negatively correlated (-0.10). Such correlations can be usefully extended to many other enzymes and to many other binding pockets to provide a general measure of pocket binding specificity.
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PMID:Binding of amino acid side-chains to S1 cavities of serine proteinases. 904 74

We report the production of human mucus proteinase inhibitor (MPI) by the filamentous fungus Aspergillus niger to test the ability of this host organism to secrete low molecular weight, highly disulfide-bonded proteins in biologically active conformation. Fungal transformants have been obtained with an expression cassette consisting of a chimeric gene founded on a mpi cDNA, encoding mature MPI, fused in frame to sequences encoding A. niger glucoamylase (glaA), separated by a KEX2-like processing sequence. Expression of the glucoamylase fusion gene in these transformants resulted in secretion of MPI into the growth medium with yields up to 3 mg 1-1. N-terminal sequence analysis of the purified inhibitor confirmed that the glucoamylase-MPI fusion protein was correctly processed to mature MPI by a KEX2-type endopeptidase present in A. niger. Furthermore, recombinant MPI retains full inhibitory activity against chymotrypsin and leukocyte elastase indicating that the protein was folded properly.
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PMID:Secretion of active human mucus proteinase inhibitor by Aspergillus niger after KEX2-like processing of a glucoamylase-inhibitor fusion protein. 908 9

The classical Bowman-Birk soybean proteinase inhibitor was modified by hydroxyethylstarch. The modified inhibitor retained the capacity for simultaneous binding of trypsin and human leukocyte elastase. The inhibition constants, Ki, of bovine trypsin, alpha-chymotrypsin and human leukocyte elastase (HLE) increased not more than 10-, 1.5-, and 20-fold, respectively, on modification of the inhibitor. The less effective inhibition is presumably due to the steric hindrance brought about by the conjugation with polysaccharide molecules. The results obtained indicate the pronounced structure differences of the binding regions for trypsin and chymotrypsin/leukocyte elastase in the modified preparation.
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PMID:Conjugation of the Bowman-Birk soybean proteinase inhibitor with hydroxyethylstarch. 917 Feb 52

Serine proteinase inhibitors (serpins) are classically regulators of extracellular proteolysis, however, recent evidence suggests that some function intracellularly. Such "ovalbumin" serpins include the human proteinase inhibitors 6 (PI-6), 8 (PI-8), and 9 (PI-9), plasminogen activator inhibitor 2, and the monocyte/neutrophil elastase inhibitor. PI-9 is a potent granzyme B (graB) inhibitor that has an unusual P1 Glu and is present primarily in lymphocytes. In a search for the murine equivalent of PI-9 we screened cDNA libraries, and performed reverse transcriptase-polymerase chain reaction on RNA isolated from leukocyte cell lines and from lymph nodes and spleens of allo-immunized mice. We identified 10 new ovalbumin serpin sequences: two resemble PI-8, two resemble PI-9, and the remaining six have no obvious human counterparts. By RNA analysis only one of the two sequences resembling PI-9 (designated SPI6) is present in mouse lymphocytes while the other (a partial clone designated mBM2A) is predominantly in testis. SPI6 comprises a 1.8-kilobase cDNA encoding a 374-amino acid polypeptide that is 68% identical to PI-9. mBM2A is 65% identical to PI-9 and over 80% identical to SPI6. Although the reactive loops of SPI6 and mBM2A differ from PI-9, both contain a Glu in a region likely to contain the P1-P1' bond. SPI6 produced in vitro using a coupled transcription/translation system formed an SDS-stable complex with human graB and did not interact with trypsin, chymotrypsin, leukocyte elastase, pancreatic elastase, thrombin, or cathepsin G. Recombinant SPI6 produced in a yeast expression system was used to examine the interaction with human graB in more detail. The second-order rate constant for the interaction was estimated as 8 x 10(4) M-1 s-1, and inhibition depended on the Glu in the SPI6 reactive center. The SPI6 gene was mapped to the same region on mouse chromosome 13 as Spi3, which encodes the murine homolog of PI-6. We conclude that even though their reactive centers are not highly conserved, SPI6 is a functional homolog of PI-9, and that the regulation of graB in the mouse may involve a second serpin encoded by mBM2A. Our identification of multiple sequence homologs of PI-8 and PI-9, and six new ovalbumin serpins, is consonant with the idea that the larger set of granule and other proteinases known to exist in the mouse (compared with human) is balanced by a larger array of serpins.
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PMID:A new family of 10 murine ovalbumin serpins includes two homologs of proteinase inhibitor 8 and two homologs of the granzyme B inhibitor (proteinase inhibitor 9). 918 75

YM-47141, a peptidic compound recently isolated from Flexibactor sp. Q17897, strongly inhibited human leukocyte elastase (HLE) with Ki value 2.1 x 10(-7) M. Unlike other serine protease inhibitors, YM-47141 exhibited relatively weak effects on cathepsin G and alpha-chymotrypsin and its inhibitory Ki values were 9.2 x 10(-4) M and 1.3 x 10(-6) M, respectively. It had little, or no inhibitory effect on plasmin, thrombin, trypsin and kallikrein (IC50 > 10(-4) M). The inhibition of HLE by YM-47141 was reversible and of a mixed type.
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PMID:Effect of YM-47141, a new inhibitor produced by Flexibactor sp. Q17897, on elastase. 920 94

Diphenyl 1-(N-peptidylamino)alkanephosphonate esters are highly reactive, specific, and aqueously stable irreversible inhibitors which can be used to probe the functions of many serine proteases, including the lymphocyte granzymes. We synthesized 16 peptide phosphonates with Ala, Met, Phe, or Val P1 amino acid residues, including two biotinylated derivatives for future functional and biochemical characterization of granzymes. The reactivity of the inhibitors was characterized with human leukocyte elastase (HLE), porcine pancreatic elastase (PPE), bovine chymotrypsin, and the granzymes of natural killer (NK) cells, which include a number of proteolytic activities (Asp-ase, Met-ase, etc.) that cleave peptide substrates with these residues in the P1 position. The reactivity and specificity of the phosphonates depended on the length and sequence of the peptidyl moiety and on the leaving group. Z-Ala-Ala-AlaP(OPh)2 was a good inhibitor of HLE and PPE (k(obsd)/[I] = 38 and 30 M(-1) s(-1), respectively) and had little reactivity with chymotrypsin. Z-Phe-Pro-Phe-P(OPh)2 was a good inhibitor of chymotrypsin (k(obsd)/[I] = 17,000 M(-1) s(-1)) and had little reactivity with the elastases. The leaving group of Z-MetP(OPh-4-Cl)2 made it a more effective chymotrypsin inhibitor than Z-MetP(OPh)2 (k(obsd)/[I] values of 142 and 30 M(-1) s(-1), respectively). With granzymes, the compounds reacted with a fraction of the Met-ase, chymase, and Ser-ase activities and lacked reactivity with Asp-ase and tryptase. Z-MetP(OPh-4-Cl)2 was an excellent inhibitor of Met-ase 1. Bi-Aca-Aca-Phe-Leu-PheP(OPh)2 appears to react specifically with one chymase while leaving other chymases untouched. Perforin-dependent lysis mediated by cytotoxic lymphocyte granules was inactivated by Z-Ala-Ala-AlaP(OPh)2, Z-MetP(OPh-4-Cl)2, Z-Leu-PheP(OPh)2, and Bi-Aca-Aca-Phe-Leu-PheP(OPh)2. The biochemical properties and biological efficacy of these inhibitors make them suitable for cellular and physiological studies of granzyme function.
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PMID:Synthesis and kinetic studies of diphenyl 1-(N-peptidylamino)alkanephosphonate esters and their biotinylated derivatives as inhibitors of serine proteases and probes for lymphocyte granzymes. 926 39


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