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)

Cancer-related urinary glycoprotein EDC1 inhibits the action of trypsin and chymotrypsin on casein and synthetic substrates. The amino acid and carbohydrate compositions of EDC1 are different from those reported for pregnancy-related urinary trypsin inhibitors.
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PMID:Antitryptic property of cancer-related glycoprotein EDC1. 14 94

In order to clarify the function of the carbohydrate moiety of bovine kappa-casein, kappa-casein components having different carbohydrate contents were prepared by DEAE-cellulose chromatography. Five adsorbed fractions so obtained had an identical peptide chain and contained carbohydrate moieties of increasing size in the order of components P-2, P-3, P-4, P-5 and P-6. The subsceptibility of kappa-casein components, having different carbohydrate contents, to various proteases was examined. kappa-Casein components were subjected to calf rennin [chymosin; EC 3.4.23.4], bovine trypsin [EC 3.4.21.4], alpha-chymotrypsin [EC 3.4.21.1], pronase [EC 3.4.24.4] and human plasmin [EC 3.4.21.7]. The component containing a larger carbohydrate moiety was less susceptible to hydrolysis than the component containing a smaller carbohydrate moiety. Rennin, trypsin, alpha-chymotrypsin and pronase hydrolyzed each component with a different reaction rate. On the contrary, human plasmin hydrolyzed component P-2, but did not hydrolyze component P-5. These results indicate that the carbohydrate moiety of kappa-casein components to various proteases.
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PMID:Susceptibility of kappa-casein components to various proteases. 15 50

1. An activator catalysing specifically conversion of latent forms of human leucocyte collagenase and gelatin-specific protease into the active forms, has been isolated from rheumatoid synovial fluid and purified 55-fold with a yield of 16%. 2. Molecular weight of the activator is about 35 000. 3. The activator is thermolabile, and is irreversibly inactivated at pH below 5.5 or in the presence of low concentrations of trypsin or papain; it is resistant to the action of lysozyme, hyaluronidase, diisopropylfluorophosphate, soybean trypsin inhibitor, p-chloromercuribenzoate, iodoacetamide and dithiothreitol. 4. The activator did not show any activity towards collagen, gelatin, casein, haemoglobin, histones, elastin or p-phenylazobenzyloxycarbonyl-peptide.
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PMID:Isolation, purification and properties of a factor from rheumatoid synovial fluid activating the latent forms of collagenolytic enzymes. 17 Jul 64

Production of a factor activating leucocyte procollagenase by tissue culture of rheumatoid synovium was shown. The activator was isolated, partly purified, and shown to be thermolabile, nondialysable, and had no activity toward casein, haemoglobin, histones, and PZ-peptide. The activity of the activator was partly decreased by trypsin.
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PMID:Activation of human leucocyte procollagenase by rheumatoid synovial tissue culture medium. 17 58

The composition of extracellular proteinases from Actinomyces fradiae 0072 and their effect on proteins and synthetic substrates were studied. The enzyme preparation was found to have keratinolytic, caseinolytic, collagenolytic, collagenase, trypsin-like, carboxy- and aminopeptidase activities. Five low molecular weight proteinases capable to hydrolyse keratin, casein, azocollagen were obtained via fractionation of the enzyme preparation on DEAE-cellulose and Sephadex columns. Proteinases from Act. fradiae and aminopeptidase with a molecular weight of 31,000 were shown to be different enzymes. In hydrolysis of L-leucyl-2-naphthylamide the Michaelis constant and Vmax of the enzyme were found to be 3.02 X 10(-3) M and 0.35 X 10(2) micronM/ml-min, respectively.
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PMID:[Characteristics of extracellular proteolytic enzymes of Actinomyces fradiae 0072]. 19 35

1. A latent neutral proteinase was found in culture media of mouse bone explants. Its accumulation during the cultures is closely parallel to that of procollagenase; both require the presence of heparin in the media. 2. Latent neutral proteinase was activated by several treatments of the media known to activate procollagenase, such as limited proteolysis by trypsin, chymotrypsin, plasmin or kallikrein, dialysis against 3 M-NaSCN at 4 degrees C and prolonged preincubation at 25 degrees C. Its activation often followed that of the procollagenase present in the same media. 3. Activation of neutral proteinase (as does that of procollagenase) by trypsin or plasmin involved two successive steps: the activation of a latent endogenous activator present in the media followed by the activation of neutral proteinase itself by that activator. 4. The proteinase degrades cartilage proteoglycans, denatured collagen (Azocoll) and casein at neutral pH; it is inhibited by EDTA, cysteine or serum. Collagenase is not inhibited by casein or Azocoll and is less resistant to heat or to trypsin than is the proteinase. Partial separation of the two enzymes was achieved by gel filtration of the media but not by fractional (NH4)2SO4 precipitation, by ion exchange or by affinity chromatography on Sepharose-collagen. These fractionations did not activate latent enzymes. 5. Trypsin activation decreases the molecular weight of both latent enzymes (60 000-70 000) by 20 000-30 000, as determined by gel filtration of media after removal of heparin. 6. The latency of both enzymes could be due either to a zymogen or to an enzyme-inhibitor complex. A thermostable inhibitor of both enzymes was found in some media. However, combinations of either enzyme with that inhibitor were not reactivated by trypsin, indicating that this inhibitor is unlikely to be the cause of the latency.
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PMID:The simultaneous release by bone explants in culture and the parallel activation of procollagenase and of a latent neutral proteinase that degrades cartilage proteoglycans and denatured collagen. 20 18

Protein kinase associated with rat liver microsomes was only partly extracted by treatment with 1.5 M KCl. The enzyme was solubilised by Triton X-100 or sodium deoxycholate at the same or slightly higher detergent concentrations than microsomal marker components. The enzyme activity increased 2-3 fold upon solubilisation. Three peaks with protein kinase activity (fractions MI, MII and MIII) were resolved on DEAE-cellulose chromatography. Fraction MIII but not fractions MI or MII was activated by adenosine 3':5'-monophosphate (cyclic AMP). All fractions catalysed the phosphorylation of protamine and histones but not that of casein or phosvitin. Fractions MI and MIII had a similar substrate specificity and phosphorylated histones at a relatively much higher rate than did fraction MII. The isoelectric points were 8.1 for fraction MI, 5.5 for fraction MII and 4.9 for fraction MIII. On incubation of fraction MIII with cyclic AMP it was split into two catalytically active components with pI 8.1 and 7.35. The component with pI 8.1 was predominant and corresponded to fraction MI. Five protein kinase peaks were resolved from rat liver cytosol by DEAE-cellulose chromatography. Three of them (fractions CIa, CIIb and CIII) had the same properties as each of the microsomal kinase fractions. A forth fraction (CIIa) was cyclic-AMP-dependent and had the same substrate specificity as fractions MI and MIII. Its pI was 5.1, and it was split into two components by cyclic AMP (pI 8.1 and 7.35). In binding studies fraction CIIb bound more efficiently to microsomes than fraction CIII, while fractions CIa, CIIa and the microsomal protein kinase fractions did not bind appreciably. When microsomes were treated with trypsin exposed protein kinase was inactivated and the latency of the remaining enzyme increased substantially. Most of fraction MII was inactivated by trypsin while fraction MIII was resistant. The possible orientation of protein kinase fractions MII and MIII in the microsomal membrane is discussed.
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PMID:Protein kinases of rat liver endoplasmic reticulum. Solubilisation, partial characterisation and comparison with protein kinases of rat liver cytosol. 20 48

Biphasic kinetic data were obtained when trypsin (EC 3.4.21.4) which had previously been complexed with a thiol-containing inhibitor (present in Ehrlich ascites tumour cells) was incubated with incremental additions of periodate. At low concentrations of periodate the trypsin was re-activated whilst at higher concentrations of periodate the trypsin was irreversibly inhibited. This biphasic reactivation followed by inhibition was also demonstrated when trypsin was first inhibited by dithiothreitol and followed by incremental addition of periodate. Similar results were obtained with chymotrypsin (EC 3.4.21.1). Incremental additions of either dithiothreitol or periodate caused inhibition of both these enzymes. The biphasic kinetic data can be explained in terms of reduction and oxidation of a significant disulphide bond in both trypsin and chymotrypsin which can be cleaved by thiols in a disulphide exchange reaction [1]. This bond is thought to maintain the active centres of each of these enzymes in a conformation sterically favourable for enzymic cleavage of specific peptide bonds in the protein substrates (polymeric collagen fibrils and casein) employed in this study.
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PMID:Inhibition of trypsin and chymotrypsin by thiols. Biphasic kinetics of reactivation and inhibition induced by sodium periodate addition. 22 48

The collagenase from the larvae Hypoderma lineatum, with a molecular weight of 24 000 and isoelectric point of 4.1, was obtained in homogeneous form by ion-exchange chromatography. It is stoichiometrically inhibited by diisopropylfluorophosphate. On the other hand it is unaffected by ethylenediaminetetraacetate, p-chloromercuribenzoate, dithiothreitol, N-tosyllysine chloromethyl ketone, N-tosylphenylalanine chloromethyl ketone and ovomucoid trypsin inhibitor. The enzyme which degrades native collagen in its helical parts, has a specific activity on thermally reconstituted collagen fibrils of 150 micrograms collagen degraded x min-1 x (mg enzyme)-1 at 37 degrees C. It hydrolyses casein but has no esterolytic activity characteristic of trypsin, chymotrypsin nor elastase. It has no action on the synthetic peptide 4-phenylazobenzyloxycarbonyl-L-prolyl-L-leucyl-L-glycyl-L-prolyl-D-arginine. The amino acid composition of Hypoderma collagenase indicates a distinct similarity with the serine proteinases of the trypsin family and with another athropode serine collagenase, that of the fiddler crab Uca pugilator. This suggests that eucaryotic collagenases with digestive rather than morphogenic function represent a new category of members of the trypsin family.
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PMID:Chemical and enzymatic characterization of the collagenase from the insect Hypoderma lineatum. 23 30

1. Complex formation of trypsin with alpha2 macroglobulin results in marked changes of the Michaelis-Menten constant, pH optimum and sensitivity to ionic strength in a system using N-carbobenzoxy-glycylglycyl-L-arginine-2-naphthylamide as substrate. 2. In contrasts to the inhibition (50%) observed when alpha2 macroglobulin-bound trypsin is assayed under conditions optimal for the free enzyme, there is minimal reduction of activity when determinations are performed at a substrate concentration and pH optimal for the bound enzyme. 3. The changes in substrate concentration and ionic environment required for maximum activity of alpha2 macroglobulin-bound trypsin are similar to those observed with enzymes embedded in polyelectrolyte matrices and may reflect alterations in the microenvironment of the enzyme resulting from conformational changes of the macromolecule during interaction with trypsin. 4. Enzymatic activity of trypsin towards casein is greatly reduced by alpha2 macroglobulin, even under assay conditions optimal for the bound enzyme, confirming previous findings that access to the active center for high-molecular weight substrates is sterically hindered by alpha2 macroglobulin.
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PMID:Effect of alpha2 macroglobulin on some kinetic parameters of trypsin. 23 90


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