Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

1. Digestive fluid proteases of the silkworm, 6B1-3, were separated, partially purified and their properties were compared. 2. These proteases were different in the substrate specificity, effect of inhibitors, Km and influence of Mn2+. 3. Hydrolyzing ability for natural substrates was comparatively high in 6B1, whereas the hydrolysis of synthetic substrates of trypsin by 6B1 was lower than that by 6B2 or 3. 4. The protease activity was sensitive to DFP and PMSF. The soybean trypsin inhibitor differentially affected three proteases. Silkworm haemolymph strongly inhibited the protease activity of 6B2 and 3, but scarcely affected 6B1.
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PMID:Comparison of three alkaline proteases from digestive fluid of the silkworm, Bombyx mori L. 704 70

When a single cell suspension of human adult marrow or fetal liver is treated briefly with trypsin, the number of erythroid bursts arising in culture is significantly increased. Erythroid colonies show less stimulation. The time to reach maximum burst number may also be shortened. The absolute increase in burst number is greater at higher concentrations of erythropoietin, suggesting a synergistic effect of trypsin treatment with that of erythropoietin. Trypsin also increases the size of the individual burst subunit. The trypsin effect is not limited to a given class of bursts as distinguished by subunit number. Other enzymes, pronase, chymotrypsin and phospholipase D, also increase burst number but to a lesser degree. The burst-stimulating effect of trypsin is enzymatic since it is completely prevented by DFP, a specific inhibitor of trypsin action.
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PMID:Trypsin enhances erythropoiesis in vitro. 740 Jun 71

Hageman factor (HF, factor XII) that has been exposed to Sephadex-ellagic acid gels is a single-chain species (HFea) with amidolytic properties for the synthetic substrate H-D-phenylalanyl-L-pipecolyl-L-arginine p-nitroanilide. Earlier we reported that amidolysis was suppressed by incubation of HFea with specific antiserum. The present study provides additional evidence that the amidolytic properties of preparations of HFea are ascribable to this substance through an examination of a number of protease inhibitors. HFea's amidolytic properties were inhibited by alpha 2-plasmin inhibitor, antithrombin III in the presence of heparin, and Cl esterase inhibitor (Cl-INH). Additionally, it was inhibited by popcorn inhibitor, leupeptin, hexadimethrine bromide, protamine sulfate, dansyl-arginine N-(3-ethyl-1,5-pentanediyl) amide (DAPA), diisopropylphosphofluoridate (DFP), aprotinin, and at excessively high concentrations, soybean and lima bean trypsin inhibitors. The spectrum of action of agents that did or did not inhibit HFea supports the view that amidolysis by preparations of HFea is attributable to this enzyme. In general, the enzymatically active carboxy-terminal fragment of HF (HFf) was inhibited by the same agents that inhibited HFea, but aprotinin, protamine sulfate and hexadimethrine bromide were more effective against HFf than HFea, while the reverse was true of lima bean trypsin inhibitor.
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PMID:Studies on the inhibition of ellagic acid-activated Hageman factor (factor XII) and Hageman factor fragments. 744 15

Six basic proteins of 26 to 38 kDa with isoelectric points (pI) > or = 8.5 were abundant in proteins separated by two-dimensional SDS-PAGE from adult rat peritoneal mast cells (MC). One was identified previously as rat mast cell proteinase (RMCP) 1, a chymase of 26 to 28 kDa, pI > 9.0. Microsequence analyses showed that two polypeptides of about 29 and 30 kDa had NH2 terminal amino acid sequences homologous to mouse MC proteinase 5 (MCP-5), whereas the amino terminals of the 33, 35, and 36 kDa proteins were homologous to MC carboxypeptidase A (MC-CPA). Rabbit Abs produced against synthetic peptides of the identified NH2 terminal sequences were used in immunoblot studies. At least three proteins reacted with Abs to MC-CPA, whereas Abs to MCP-5 detected three adjacent polypeptides, rather than just the two identified by using microsequence analysis. Removal of oligosaccharide side chains using peptide:N-glycosidase F reduced the heterogeneity of each set of three polypeptides (MCP-5 and MC-CPA) to a band of each protein of a lower M(r). The serine proteinase inhibitor [3H]diisopropylfluorophosphate ([3H]DFP) bound to a proteinase of 30 to 35 kDa, which is probably MC tryptase (pI < or = 6.0). Immunoblot analysis of proteins from intestinal mucosal mast cells showed RMCP-2, but not RMCP-1, MCP-5, or MC-CPA. This is the first report of MCP-5 in the rat and of clearly distinguishable glycosylated forms of MC CPA. These proteinases appear to be restricted in their distribution to selected MC populations, but little is known about their functions.
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PMID:Proteinases of rat mast cells. Peritoneal but not intestinal mucosal mast cells express mast cell proteinase 5 and carboxypeptidase A. 759 1

The principal digestive proteinases of the gypsy moth, Lymantria dispar, larval midgut were identified, and the subcellular distribution of the enzyme activities was determined. Proteinase activities of fifth-instar larvae were largely attributed to two luminal serine proteinases, a trypsin-like enzyme (TLE) and an elastase 2-like enzyme (ELA). TLE was purified to homegeneity by benzamidine-Sepharose affinity chromatography. With respect to size (M(r) = 25 kDa), substrate specificity, and interaction with trypsin inhibitors, the gypsy moth enzyme resembled mammalian pancreatic trypsin and trypsin-like enzymes from other insects. Gypsy moth elastase (ELA) was purified from the benzamidine-Sepharose flow-through by mono-Q FPLC. ELA exhibited a slightly smaller size (M(r) = 24 kDa) than TLE. The insect enzyme was inhibited by DFP and chymostatin but was unaffected by TPCK. ELA exhibited little esterolytic activity with BTEE. Succinyl-Ala-Ala-Pro-Leu p-nitroanilide was one of the best substrates for ELA, which is characteristic of elastase 2. TLE and ELA constituted c. 6% of the total soluble protein in midgut lumen of actively feeding fifth-instar larvae. Chymotrypsin and carboxypeptidase activities were not detected in any midgut fraction examined. The brush border membrane (BBM) leucine aminopeptidase (LAP) was isolated from CHAPS-solubilized BBM by FPLC. SDS-PAGE results indicated that the aminopeptidase has an apparent molecular size of c. 100 kDa. The aminopeptidase was inhibited by bestatin and was unaffected by serine proteinase inhibitors.
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PMID:Gypsy moth midgut proteinases: purification and characterization of luminal trypsin, elastase and the brush border membrane leucine aminopeptidase. 771 46

Two high molecular mass proteinases, multicatalytic proteinase (MCP) and a new high molecular mass proteinase (HMP) with only chymotrypsin-like activity (Khan et al. (1994) J. Biol. Chem. 269, 10016-10021) from human erythrocyte membranes, have been compared. For this purpose, MCP was purified from human erythrocyte membranes in the active form towards synthetic peptide substrates; it also hydrolysed the protein substrates [14]methyl casein and [14C]oxidised insulin beta chain at 37 degrees C. MCP from plasma membranes exhibited hollow cylindrical structures also typical of cytosolic forms. Radiolabelled diisopropyl fluorophosphate, [3H]DFP, a serine proteinase inhibitor, labelled a band of Mr 23 000 in membrane MCP. By contrast, no labelling was obtained with HMP. Chymotrypsin-like activity of HMP was also found to be insensitive to DFP. On the other hand, DFP inhibited chymotrypsin-like and peptidylglutamyl peptide hydrolysing activities of membrane MCP, with no effect on its trypsin-like activity. The inhibition of MCP by DFP was concentration-dependent. These studies showed that MCP and HMP represent two distinct kinds of proteinases with chymotrypsin-like activities and can be distinguished by the serine proteinase inhibitor DFP.
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PMID:Membrane-bound high molecular mass proteinases from human erythrocytes. 781 93

To characterize the structure of the active site of acetylcholinesterase (AChE) from the electric organ of E. electricus, we identified sites of incorporation of two active-site affinity labels, [3H]diisopropyl fluorophosphate ([3H]DFP), and 1-bromo-2-[14C]pinacolone ([14C]BrPin). AChE was isolated, purified, inactivated and digested with trypsin, and peptides containing 3H or 14C were purified by reverse-phase HPLC and characterized by N-terminal sequence analysis. [3H]DFP, labelling Ser-200, was found in a single peptide, QVTIFGESAGAASVGMHLLSPDSR, 83% identical with the sequence from Thr-193 to Arg-216 deduced for AChE of T. californica, with Gln, Ala, Leu, and Asp in place of Thr-193, Gly-203, Ile-210 and Gly-214, respectively, and 87% identical with that from bovine and human brain AChEs. Inactivation by [14C]BrPin led to two radioactive peptides. One, ASNLVWPEWMGVIHGYEIEFVFGLPLEK, was 96% identical with that extending from Ala-427 to Lys-454 of T. californica. Release of 14C in cycle 14 established reaction of [14C]BrPin with active-site His-440, protected by 5-trimethylammonio-2-pentanone (TAP). The other peptide, LLXVTENIDDAER, 77% homologous with that of T. californica extending from Leu-531 to Arg-543, had label associated with the third cycle, not protected by TAP, corresponding to Asn-533. The slow inactivation of eel AChE by reaction of [14C]BrPin at His-440 contrasts with that of AChE from T. nobiliana, where it reacts rapidly with a free cysteine, Cys-231, not present in eel AChE. For both AChEs, inactivation by BrPin prevents subsequent reaction with [3H]DFP, and prior inactivation by DFP does not prevent reactions with [14C]BrPin.
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PMID:Active-site peptides of acetylcholinesterase of Electrophorus electricus: labelling of His-440 by 1-bromo-[2-14C]pinacolone and Ser-200 by tritiated diisopropyl fluorophosphate. 794 65

Bovine lens alpha-crystallin inhibited both porcine pancreatic elastase (PPE) and human neutrophil elastase (HNE), but not in the same manner. PPE was immediately inhibited with a stoichiometry of 10 moles of PPE inhibited per mole of alpha-crystallin. The inhibition was markedly decreased by the addition of even low levels of salts. The inhibition was transient, as PPE activity returned to normal with a t1/2 of 30 min even in low salt. HNE required a short preincubation to show maximum inhibition with a stoichiometry of approximately one mole of HNE inhibited per mole of alpha-crystallin. The inhibition of HNE was only slightly decreased by the addition of 0.1 M salt, and HNE activity returned slowly exhibiting a t1/2 of 30 hrs under these conditions. The inhibition of each enzyme by alpha-crystallin was evaluated by Dixon plots giving Ki values of 1.5 nM for PPE and 0.25 nM for HNE. DFP-trypsin was able to compete with PPE for binding to alpha-crystallin and cause the release of PPE already bound to alpha-crystallin. The inhibition of HNE, however, was unaffected by the addition of DFP-trypsin. A mixture of HNE and alpha-crystallin in 0.1 M NaCl was incubated at 25 degrees C for 6 hours. Aliquots showed a slow, continuous cleavage of the alpha-crystallin subunits by SDS-PAGE, but little or no increase in HNE activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A comparison of the inhibition of porcine pancreatic elastase and human neutrophil elastase by alpha-crystallin. 795 8

The trypsin from Fusarium oxysporum is equally homologous to trypsins from Streptomyces griseus, Streptomyces erythraeus and to bovine trypsin. A DFP (diisopropylfluorophosphate) inhibited form of the enzyme has been crystallized from 1.4 M Na2SO4, buffered with citrate at pH 5.0-5.5. The crystals belong to space group P2(1) with cell parameters a = 33.43 A, b = 67.65 A, c = 39.85 A and beta = 107.6 degrees. There is one protein molecule in the asymmetric unit. X-ray diffraction data to a resolution of 1.8 A were collected on film using synchrotron radiation. The structure was solved by molecular replacement using models of bovine and S. griseus trypsins and refined to an R-factor of 0.141. The overall fold is similar to other trypsins, with some insertions and deletions. There is no evidence of the divalent cation binding sites seen in other trypsins. The covalently bound inhibitor molecule is clearly visible.
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PMID:The sequence and X-ray structure of the trypsin from Fusarium oxysporum. 833 90

Moulting fluid of pharate adult tobacco hornworm moths, Manduca sexta, contains a novel cuticle-degrading proteinase, designated as MFP-1. The enzyme has been purified using heparin affinity chromatography and partially characterized. Before purification MFP-1 is associated with a large complex having an apparent native molecular mass > 669 kDa. After purification MFP-1 has a molecular mass of 41 kDa. The pI of the enzyme is 5.54. MFP-1 can be classified as generally trypsin-like on the basis of its substrate specificity and inhibition by soybean trypsin inhibitor. The enzyme's preferred substrate, Tos-Gly-Pro-Arg-pNA, its inhibition by hirudin, and its affinity for heparin, all indicate that MFP-1 has some characteristics in common with the vertebrate blood-clotting enzyme thrombin. MFP-1 is probably a serine protease, since it is inhibited by both DFP and PMSF (specific inhibitors of serine proteinases). However, the enzyme was also inhibited by a number of agents that affect cysteine proteinases. Purified MFP-1 degrades Manduca cuticle in vitro. We suggest that the enzyme may act as the first step in the degradation of the cuticle during the moulting process.
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PMID:A cuticle-degrading proteinase from the moulting fluid of the tobacco hornworm, Manduca sexta. 835 21


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