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)

Two proteinases (2A and 2B) purified from the granular fraction of horse blood leucocytes degrade casein (Km values 12.8 and 6mg/ml respectively) with maximum activity at pH 7.4 and in the presence of 2m-urea. Urea-denatured haemoglobin, fibrinogen, albumin and resorcin/fuchsin-stained elastin are digested at a slower rate. The enzymes hydrolyse synthetic substrates of elastase, N-benzyloxycarbonyl-L-alanine 4-nitrophenyl ester (Km 0.114 and 0.178 mM) and N-acetyl-tri-L-alanine methyl ester (Km 5.55 and 0.98 mM), but they do not hydrolyse synthetic substrates of trypsin, chymotrypsin and thrombin. The examined proteinases are completely inhibited by 2 mM-di-isopropyl phosphorfluoridate and show a sensitivity to butyl and octyl isocyanates similar to that of pancreatic elastase. The pH-dependence of their photoinactivation in the presence of Rose Bengal indicates the presence of histidine in the active centre. Proteinase 2A rather insensitive to iodination by IC1 as is pancreatic elastase, whereas proteinase 2B is totally inactivated after incorporation of five iodine atoms per enzyme molecule.
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PMID:Substrate specificity and modifications of the active centre of elastase-like neutral proteinases from horse blood leucocytes. 0 9

1. alpha 1-Proteinase inhibitor was isolated from human plasma by a five-step procedure. Isoelectric focusing showed that six components focused between pH4.85 and 4.95. 2. The mol.wt. of the inhibitor was 52000 by sedimentation equilibrium and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The amino acid and carbohydrate compositions of the inhibitor were also determined. 3. The far-u.v.c.d. (circular-dichroism) spectrum indicated that the inhibitor had about 36% alpha-helical content. 4. The loss of proteinase-inhibitory activity when the inhibitor was exposed to pH values less than 5.0 or greater than 10.5 was accompanied by small changes in the far-u.v.c.d. spectrum and large changes in the near-u.v.c.d. spectrum. The change at alkaline pH was associated with ionization of tyrosine residues. 5. Interaction of inhibitor with chymotrypsin caused perturbation of the c.d. spectrum and this was used to follow the interaction and show a 1:1 stoicheiometry. 6. C.d., electrophoresis and isoelectric focusing showed that the inhibitor-enzyme complex is degraded by free enzyme. 7. Parallel studies with trypsin indicated that it too forms a 1:1 complex with inhibitor and is degraded by excess of enzyme.
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PMID:Isolation and characterization of human plasma alpha 1-proteinase inhibitor and a conformational study of its interaction with proteinases. 0 69

In untreated patients with inoperable lung cancer, serum levels of alpha1-antitrypsin were found significantly increased in comparison to patients with non malignant diseases of the lung, alpha2-macroglobulin levels were unchanged in both groups of patients. There was also no difference in alpha2-macroglobulins in cancer patients reacting with DNCB and in non-reactors. Thus alpha2-macroglobulin levels do not seem to correlate with the immunestatus of cancer patients. Proteinase inhibitors are involved in a variety of biological processes including blood, clotting, digestion, and sperm capacitation. alpha1-antitrypsin, a alpha-globulin with a molecular weight of about 60,000 has been found to be decreased in patients' serum under several pathological conditions. A clear correlation exists between alpha1-antitrypsin deficiency and hereditary pulmonary emphysema (1, 2), respiratory distress syndrome (3), and juvenile cirrhoses of the liver (4). Elevated serum levels of alpha1-antitrypsin have also been found in some cancer cases. Thirty years ago a cancer test was developed on the basis of differences in the antiproteolytic activity in cancer patients' sera and in patients with other non-neoplastic diseases (5, 6). Several authors have tried to confirm these early data regarding specifity and sensitivity with respect to a screening test for cancer (7, 8). Methods of these authors were based mainly on enzyme substrate inhibition assays by addition of the patients' sera. Recently a commercially available test, based on immune-precipitation according to Mancini (9), has been developed (Behring-Werke, Partigen). By using this standardized method for determinating alpha1-antitrypsin, Harris et al. have recently demonstrated that patients with inoperable lung cancer have significantly elevated levels of this antiprotease in their sera (10), in comparison to patients with non malignant diseases of the lung. alpha2-macroglobulin is a serum protein with a molecular weight of 800,000 and with known antiprotease activity and can therefore bind trypsin, plasmin, elastase, and collagenase and it is known that alpha2-macroglobulin decreases with increasing of age. Changes of alpha-macroglobulin have also been observed in several pathological conditions (11). James et al. 4ave found decreases in serum of myeloma patients (12). An association between the development and function of lymphocytes and alpha2-macroglobulin has been suggested by several authors (13, 14). This alpha2-globulin has also been demonstrated on the surface of peripheral blood lymphocytes (15) and there is evidence that it is synthesized by lymphocytes (16). The purpose of the present study was to determine serum alpha1-antitrypsin levels in patients with inoperable lung cancer and to determine whether there is also an inverse correlation to alpha2-macroglobulin. It was further attempted to correlate alpha2-macroglobulin with general immunological parameters, as it is known that patients with lung cancer show a decreased general immune-reactivity (17).
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PMID:Serum levels of alpha1-antitrypsin and alpha2-macroglobulin in lung cancer. 6 86

Two proteinases (proteinases I and II) have been purified from Crotalus adamanteus venom to the stage of electrophoretic homogeneity and proteinase II has been crystallized. The proteinase differ slightly in molecular weight and amino acid composition. Both are metalloenzymes requiring Zn2+ or Ca2+, or both; neither requires thiol compounds for activation. The proteinases are free of esterolytic activity against benzoly-L-arginine ethyl ester and benzoyl--tyrosine ethyl ester. Proteinase II cleaves the oxidized B chain of insulin at the bonds Phe1-Val2, His5-Leu6, His10-Leu11, Ala14-Leu15, Leu15-Tyr16, and Tyr-16-Leu17. Digestion of polylsine and polyarginine by proteinase II liberates products ranging from dodecapeptides to hexapeptides. Proteinases I and II catalytically inactive human plasma alpha 1-proteinase inhibitor (54,000 daltons). Electrophoretic analysis of the reaction of proteinase II with alpha 1-proteinase inhibitor reveals that an inactivated inhibitor species of 50,000 daltons is formed, and a peptide of 4,000 daltons is released. The gradual disappearance of the native inhibitor results in the corresponding loss of inhibitory activity against trypsin and chymotrypsin.
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PMID:Purification and some properties of two proteinases from Crotalus adamanteus venom that inactivate human alpha 1-proteinase inhibitor. 30 70

Proteinase k, a seryl-protease obtained from Tritirachium album, is able to specifically hydrolyze N-blocked aminoacyl transfer ribonucleic acids (tRNAs). The blocked amino acid is released, and the tRNA molecule remains able to be recharged by its cogante amino acid. Aminoacyl-tRNAs are highly resistant to hydrolysis by the protease. This activity is not due to contamination of the protease preparation. A commercial protease from Streptomyces griseus displayed a similar activity, while trypsin, chymotrypsin, and papain unspecifically hydrolyzed all charged tRNAs tested. The characteristics of the hydrolysis performed by proteinase k closely resemble the peptidyl-tRNA hydrolase activity described in different cells as a scavenger for the peptidyl-tRNA that eventually falls from the polysomes. Out results warn about a hasty identification of any N-blocked aminoacyl-tRNA hydrolase activity in the cytoplasm as an independent peptidyl-tRNA hydrolase.
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PMID:Peptidyl transfer ribonucleic acid hydrolase activity of proteinase k. 38 46

Proteinase inhibitor II, an inhibitor of chymotrypsin and trypsin, is a heat-stable protein with a dimeric molecular weight of 21 000 that is a component of Russet Burbank potato tubers. Four monomeric isoinhibitor species of molecular weight 10 500 comprise inhibitor II and were isolated by chromatography on phosphocellulose in 8 M urea. Upon removal of the urea, each monomeric species dimerized to yield homogeneous dimers. The three major protomer species, called B, C, and D, and their homogeneous dimers were further characterized. They have similar molecular weights and amino acid compositions, and each has an N-terminal alanine residue. Dimers of purified protomers B, C, and D exhibited full cross-reactivities with each other in immunological double-diffusion assays. Reconstituted dimers possess two binding sites for bovine alpha-chymotrypsin, indicating that each monomer possesses one binding site for this enzyme. Significant differences were noted among the reconstituted dimers in their isoelectric points, immunoelectrophoretic mobilities, ion-exchange properties, and their inhibitory reactivities against trypsin. The properties of the inhibitor II dimeric species are similar but not identical to inhibitors IIa and IIb reported from Japanese potatoes (variety "Danshaku-Imo"), indicating the existence of intervarietal, as well as intravarietal, differences among potato tuber inhibitor II isoinhibitors.
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PMID:Proteinase inhibitor II from potatoes: isolation and characterization of its protomer components. 82 19

Both the clotting and esterase activities of thrombin are inhibited by alpha1-proteinase inhibitor (alpha1-antitrypsin). The inhibition is a time-and temperature-dependent reaction which is proportional to the molar ratio of thrombin to inhibitor. Both the active-site serine residue of thrombin and the reactive-site lysine residue of alpha1-proteinase inhibitor are involved. alpha1-Proteinase inhibitor forms a 1:1 complex with thrombin that is comparable with the complex formed with trypsin and other proteinases. Incubation of the inhibitor with excess of thrombin, however, results in inactivation of nearly all the enzyme, even though only as much complex is formed as alpha1-proteinase inhibitor present. A portion of the remaining thrombin apparently aggregates. These results suggest that the mechanism for inhibition of thrombin may not be exactly the same as for trypsin, which is inhibited only to the extent to which complex is formed.
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PMID:Inactivation of human thrombin in the presence of human alpha1-proteinase inhibitor. 108 57

Proteinase inhibitors were isolated from Scopolia japonica cultured cells. Isolation procedures involve concentration by a hydrophobic resin of Diaion HP-20, decolorization by Duolite A-7, affinity chromatography on trypsin-Sepharose, and Bio-Gel P-4 chromatography. It was found that the proteinase inhibitors from S. japonica cells are a mixture of at least five components. For the inhibitory components except one, amino acid analyses, measurements of sedimentation equilibrium and optical rotatory dispersion (ORD) were carried out. The inhibitors were shown to be the polypeptides with molecular weights in the range of approximately 4000 to 6000. In addition, one of them was found to have approximately 15% alpha-helical conformation by the Moffitt-Yang analysis of ORD data. The inhibitors were found to have potent inhibitory activity for trypsin, chymotrypsin, plasmin, kallikrein and pepsin but not for papain with synthetic and natural substrates. These inhibitors formed stable complexes with trypsin and chymotrypsin in an equimolar ratio, and their inhibitory mechanisms for both enzymes were of non-competitive type.
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PMID:Broad-specificity proteinase inhibitors in Scopolia japonica (Solanaceae) cultured cells. Isolation, physicochemical properties, and inhibition kinetics. 117 2

We previously found a trypsin-like proteinase which momentarily appears immediately before DNA synthesis in the cell cycle of Escherichia coli synchronized by phosphate starvation and which is closely related to the initiation of DNA replication (Kato, M., Irisawa, T., Morimoto, Y. and Muramatu, M., unpublished results). The proteinase was named proteinase In. It was purified approximately 2880-fold with a recovery of 15%. The isolated enzyme appeared homogeneous by gel filtration and electrophoresis. Its molecular mass was estimated by analytical gel filtration and SDS/PAGE as approximately 66 kDa. The isoelectric point of proteinase In is 4.9 and its optimal pH is approximately 9. Although protein In hydrolyzes fluorogenic substrate for trypsin, its hydrolytic activity seems markedly affected by amino-acid sequence lying towards the N-terminal from the P1 (lysine, arginine) residue. The proteinase does not hydrolyze N2-benzoyl-D,L-arginine-4-nitronanilide and fluorogenic substrates for chymotrypsin and elastase. The proteinase activity is inhibited by leupeptin, antipain and 4-nitrophenyl 4-guanidinobenzoate, but the effects of tosyl-L-lysine chloromethane, diisopropylfluorophosphate, benzamidine and pentamidine isethionate on the proteinase activity are weak or not inhibitory. Its activity is strongly affected in the presence of NaCl and KCl, and at a concentration of 1.5 M, these increase the activity 14-fold and 13-fold, respectively, above that without salt. Proteinase In was strongly inhibited by various esters of trans-4-guanidinomethylcyclohexanecarboxylic acid, and their inhibitory effects were roughly correlated with those on growth of E. coli. Proteinase activity was found in the cytoplasmic fraction.
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PMID:Purification and characterization of proteinase In, a trypsin-like proteinase, in Escherichia coli. 133 54

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


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