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)

We have studied an indirect role of serine and thiol proteases in the activation of human neutrophils in vitro. Stimulation was evaluated using a chemiluminescence (CL) generation system. Receptor-dependent and receptor-independent stimuli were studied, e.g. opsonized zymosan, formyl-methionyl-leucyl-phenylalanine, platelet activating factor, phorbol myristate acetate, and calcium ionophore A23187. The serine protease inhibitors TPCK and TLCK, and thiol protease inhibitor PHMB, diminished the CL with different potencies and in a dose-dependent manner after treatment of cells with the various stimuli. Non-specific serine protease inhibitor, PMSF, and trypsin substrate TAME, showed a low inhibitory potency with respect to CL generation. Synthetic substrates for chymotrypsin (BTEE, ATEE) significantly inhibited CL with the various stimuli used with some differences in susceptibility to their inhibition. Specific chymotrypsin inhibitors diminished both the resting and activator-induced CL. We suggest that cell-bound chymotrypsin-like protease(s) is involved in the activation of signal transduction in human neutrophils after both receptor-dependent and receptor-independent stimulation.
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PMID:The effect of serine and thiol protease inhibitors on the chemiluminescence of human neutrophils in investigations in vitro. 164 40

The picornavirus 3C proteinases are substrate-specific thiol proteases that have been shown by secondary structure predictions and protein modeling studies to be similar to the trypsin-like serine proteases. We have examined several mutations of the 3C proteinase at putative active site and non-active site residues. The effect on 3C-mediated protein processing supports the model of serine protease similarity. In particular, we have shown that 3C can utilize a serine at position 147, which is predicted to supply the nucleophilic residue of the catalytic triad. We suggest that picornavirus 3C proteinases may represent a class of enzymes that have maintained the catalytic mechanism characteristic of a proposed enzyme ancestral to the highly divergent class of serine proteases.
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PMID:Poliovirus thiol proteinase 3C can utilize a serine nucleophile within the putative catalytic triad. 165 4

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

A cDNA clone encoding an anionic form of bovine trypsinogen was isolated from a pancreatic cDNA library. The corresponding 855-nucleotide mRNA contains a short 5' noncoding region of 8 nucleotides and a long 3' noncoding region of 56 nucleotides in addition to a poly(A) tail of at least 50 nucleotides. The deduced amino acid sequence for the anionic pretrypsinogen (247 residues) includes the N-terminal 15-amino-acid signal peptide followed by an 8-amino-acid activation peptide. The zymogen (232 residues) contains an additional C-terminal serine, compared with the amino acid sequence of bovine cationic trypsinogen. The identity between the anionic and cationic forms of bovine trypsinogen (65%) is lower than that existing between the anionic protein and other mammalian anionic trypsinogens (73-85%), suggesting that trypsin gene duplication in mammals occurred prior to the evolutionary events responsible for the species divergence. Bovine pancreatic anionic trypsin possesses all the key amino acids characteristic of the serine protease family.
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PMID:Isolation and nucleotide sequence of cDNA clone for bovine pancreatic anionic trypsinogen. Structural identity within the trypsin family. 170 Nov 47

Human duodenal juices collected during tube instillation of raw soybean extract into the duodenum contained free trypsin and free Kuntiz soybean trypsin inhibitor (KTI) in the simultaneous presence of trypsin-KTI complexes. It has previously been suggested that this KTI-non-inhibitable trypsin has a general resistance to serine protease inhibitors. Four different trypsin forms have been found and partly characterized by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and isoelectric focusing followed by Western immunoblotting or enzyme staining. In addition, crossed immunoelectrophoresis and affinity chromatography with antibody-coupled gels have been used for identification of free and inhibitor-complexed trypsin.
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PMID:Characterization of a human trypsin resistant to Kunitz soybean trypsin inhibitor. Studies of duodenal juices after tube instillation of raw soybean extract. 171 6

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 previous findings that the group I and III mite allergens, and amylase present in mite faeces are hydrolytic enzymes has prompted a study to determine whether this material contains other enzymes which could be allergenic. Thus, spent growth medium devoid of whole Dermatophagoides pteronyssinus mites was shown to contain glucoamylase, lipase and lysozyme in addition to the cysteine protease, serine protease and amylase activities associated with the above allergens, respectively. All of these enzymes are probably associated with mite digestive processes. They were rapidly solubilised, heterogeneous with regard to charge (pI in the range 4-8) and demonstrated maximum biochemical activity in the neutral pH range. Three serine proteases were detected and comprised a chymotrypsin-like, a trypsin-like and an unclassified enzyme with pI of 4.1 and 5.3, 8.5 and 7.1, respectively. Only one cysteine protease was observed, which paralleled immunochemically identified Der p I in a variety of assays. It was shown to cleave at lysyl residues and could be inhibited by the specific cysteine protease inhibitor, E-64. The remaining serine proteases, glucoamylase, lipase and lysozyme represent potential allergens.
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PMID:Faecally derived hydrolytic enzymes from Dermatophagoides pteronyssinus: physicochemical characterisation of potential allergens. 171 11

We have purified a protein from the granules of the rat NK leukemia cell line (RNK) that is cytostatic to a variety of tumor cells. This protein shows no species specificity because certain tumor cell lines of mouse, rat, and human origin were equally sensitive to its growth inhibitory effects. Treatment of sensitive cells resulted in a rounding of the cells followed by homotypic aggregation into large aggregates. The granule protein was distinct from cytolysin, Na-Cbz-Lys-thiobenzylester-esterase, or leukolexin. It had a molecular mass of 29 to 31 kDa, bound strongly to heparin, was inactivated by heating at 70 degrees C for 5 min or reduction, but was stable to trypsin treatment. By using molecular sieve chromatography, heparin agarose chromatography, and reverse phase HPLC, this protein was purified to homogeneity. The first 33 amino acids of the N-terminal amino acid sequence showed complete identity to the sequence predicted from a rat serine protease gene recently cloned and designated RNKP-1. Therefore we have purified a novel serine protease and demonstrated that it has effects on the growth and morphology of certain tumor cells. Other serine proteases that were structurally related and have substantial homology with RNKP-1 at the amino acid level showed neither growth inhibitory properties nor affected the morphology of the tumor target cells we used.
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PMID:Purification of a factor from the granules of a rat natural killer cell line (RNK) that reduces tumor cell growth and changes tumor morphology. Molecular identity with a granule serine protease (RNKP-1). 172 74

A soluble 80-kDa endopeptidase has been isolated from Trypanosoma brucei brucei. The enzyme, which has a pI 5.1, is optimally active at about pH 8.2 and has apparent pKa values of 6.0 and greater than or equal to 10. It is inhibited by the serine protease inhibitor diisopropylfluorophosphate and by the serine protease mechanism-based inhibitor 3,4-dichloroisocoumarin. Unexpectedly, the enzyme is inhibited by the cysteine protease inhibitor benzyloxycarbonyl-Leu-Lys-CHN2 but not by the related diazomethane, butoxycarbonyl-Val-Leu-Gly-Lys-CHN2, nor by other cysteine protease specific compounds. Specificity studies with a variety of amidomethylcoumaryl (AMC) derivatives of small peptides show that the enzyme has a highly restricted trypsin-like specificity. The best substrate, based on the magnitude of kcat/Km, was benzyloxycarbonyl-Arg-Arg-AMC; other good substrates were benzyloxycarbonyl-Phe-Arg-AMC, benzoyl-Arg-AMC, and compounds with Arg at P1 and Ala or Gly at P2. The hydrolysis of most substrates obeyed classical Michaelis-Menton kinetics but several exhibited pronounced substrate inhibition. The enzyme did not activate plasminogen nor decrease blood clotting time; it was inhibited by aprotinin but not by chicken ovomucoid. We conclude that the enzyme is a trypsin-like serine endopeptidase with unusually restricted subsite specificities.
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PMID:Characterization of an endopeptidase of Trypanosoma brucei brucei. 173 36

The three-dimensional structure of soybean trypsin/chymotrypsin Bowman-Birk inhibitor in solution has been determined by two-dimensional 1H nuclear magnetic resonance spectroscopy and dynamical simulated annealing using the program XPLOR. The structure was defined by 907 NOEs involving intra- and interresidue contacts which served as distance constraints for a protocol of dynamical simulated annealing. In addition, 48 phi angle constraints involving non-proline amino acids, 29 chi angle constraints, six omega angle constraints for the X-Pro peptide bond, and 35 stereoassignments for prochiral centers were incorporated during the course of the calculation. The protein is characterized by two distinct binding domains for serine protease. Each domain is comprised of a beta-hairpin (antiparallel beta-sheet and a cis-proline-containing type VIb reverse turn) with a short segment making a third strand of antiparallel beta-sheet. The structure determination and refinement are described, and the structure is compared to other structures of Bowman-Birk inhibitors as well as other families of serine protease inhibitors.
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PMID:Three-dimensional structure of soybean trypsin/chymotrypsin Bowman-Birk inhibitor in solution. 173 75


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