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

---

Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fibrinolytic activity of normal plasma and blood has been measured by 125l-fibrin solid phase assay. Activity of plasma is not affected by removal of plasminogenplasmin by affinity chromatography. Activities of euglobulin and pseudoglobulin fractions are approximately equal. epsilon-aminocaproic acid (EACA) (10 mM), tranexamic acid (10 mM), diisopropylfluorophosphate (DFP, 50 mM), and soybean and lima bean trypsin inhibitors (100 mug/ml) do not inhibit plasma activity at concentrations that inhibit pure plasmin and urokinase-activated plasma. Activity is not affected by glass contact and is not inhibited by inhibitors of contact or enzymatic activation of Hageman factor (hexadimethrine bromide, 100 mug/ml; cytochrome C, 250 mug/ml; spermidine, 2 mM; phenylmethylsulfonylfluoride, 1 mM). It is inhibited partially (30%-40%) by heating (56 degrees C, 30 min) and by zymosan (2.5 mg/ml; 40%-90% inhibition), and is increased by hydrazine (20 mM), salicylaldoxime (20 mM), DFP (50 mM), and tosyl-L-arginine methyl ester (TAMe, 10 mM)-the latter two at concentrations known to inhibit Cls of the classic, and factor D of the alternate complement pathways. Increase fibrinolytic activity with TAMe is associated with reciprocal decrease in classic and alternate complement pathway activity. It is concluded that normal plasma fibrinolytic activity is relatively independent of plasmin as the ultimate fibrinolytic enzyme, that Hageman factor-dependent pathways are of minor importance, and that significant heat-stable and heat-labile nonplasmin fibrinolytic activities are operative. These may include proteinases involved in complement activation, and in common control of classic and alternate complement pathways, as well as other nonplasmin proteinases.
...
PMID:Fibrinolysis in normal plasma and blood: evidence for significant mechanisms independent of the plasminogen-plasmin system. 13 51

Trypsin, thrombin, fibrinolysin, papain, chymothrypsin and urokinase were immobilized on aminopolystyrene resin by the reaction of diazocoupling. An activation of prothrombin and plasminogen and also hydrolysis of fibrin by immobilized enzymes were studied. The immobilized enzymes hydrolyzed N-benzoyl-1-arginine ethyl ester and L-tyrosine ethyl ester. The only preparation of immobilized thrombin possessed the coagulational activity. After the covalent binding trypsin and plasmin maintained the capacity to cause a fibrinolysis. Immobilized trypsin, plasmin, papain, chymotrypsin and urokinase exhibited the fibrinolytic effect due to convertion of plasminogen into plasmin.
...
PMID:[Blood coagulating properties of immobilized proteases]. 14 May 25

p-Nitrobenzyl p-toluenesulfonyl-L-arginine has been synthesized. A number of trypsin-like enzymes can catalyze the hydrolysis of this ester leading to formation of p-nitrobenzyl alcohol. After separation from the ester and p-toluenesulfonylarginine by extraction into chloroform, the p-nitrobenzyl alcohol liberated can be measured spectrophotometrically at 271 nm. Under the conditions of the assay, the hydrolysis of 1 micronmol/ml of the ester is equivalent to an absorbance change of 4.45 cm-1 at 271 nm. With 0.10 mM p-nitrobenzyl p-toluenesulfonyl-L-arginine in 0.1 M Tris-HCl at pH 8.4 and 30 degrees, the enzymatic hydrolysis is linearly proportional to time up to consumption of 60% of the ester. Product formation is proportional to enzyme concentration with 0.05 to 0.2 NIH clotting units/ml for bovine or human thrombin, 0.005 to 0.02 CTA units/ml for human plasmin, and 0.01 to 0.04 microgram/ml protein for bovine pancreatic trypsin. In 0.1 M Tris-HCl at pH 8.4 and 30 degrees, Km is 14 micrometer and Vmax is 0.037 micronmol/min/NIH unit/ml for bovine thrombin, Km is 78 micrometer and Vmax is 0.31 micronmol/min/CTA unit/ml for human plasmin, and Km is 12 micrometer and Vmax is 138 micronmol/min/mg protein/ml for bovine trypsin. With bovine thrombin, activities at pH 7.3 and at pH 9.2 were 30% lower and 40-50% higher than the rate at pH 8.4. Samples of bovine and human thrombin ranging in specific clotting activity from 59 to 2133 NIH units/mg protein showed esterase activities varying from 0.15 to 0.4 micronmol p-nitrobenzyl alcohol formed/10 min/NIH unit.
...
PMID:Assay of the esterase activity of thrombin, plasmin and trypsin with a chromogenic substrate p-nitrobenzyl p-toluenesulfonyl-l-arginine. 14 54

Photophosphorylation by spinach chloroplasts is inhibited after they have been incubated in the dark with either phenylglyoxal or butanedione. Inhibition by phenylglyoxal is strongest when N-ethylmorpholine is the buffer used during the incubation; that by butanedione requires the presence of borate as buffer. The inhibitions are not reversed by simply washing out the inhibitor, suggesting that a covalent modification of one or more arginine residues is responsible. This is supported by the reversibility of the butanedione inhibition if both the inhibitor and borate buffer are removed. ATPase of the chloroplasts, and of extracted protein, is inhibited, whether activated by trypsin or by heating. This indicates that arginine residues of the coupling factor are the probable major site(s) for attack by these modifiers, leading to the observed inhibitions.
...
PMID:Arginine modifiers as energy transfer inhibitors in photophosphorylation. 14 62

Rates of hydrolysis of the newly developed peptide chromogenic substrates S-2160 (N-Bz-Phe-Val-Arg-pNA, HCl), S-2238 (H-D-Phe-Pip-Arg-pNA, 2HCl), S-2222 (N-Bz-Ile-Glu-Gly-Arg-pNA, HCl), and S-2251 (H-D-Val-Leu-Lys-pNA, 2HCl) from AB Kabi Peptide Research and Chromozym TH (Z-Gly-Pro-Arg-pNA, HCl) from Pentapharm Limited were tested against highly purified preparations of human plasmin, bovine trypsin, human alpha thrombin, and bovine factor Xa. S-2160, S-2238, and Chromozym TH are sensitive to thrombin, Chromozym TH and S-2238 exhibiting a substantially greater sensitivity than S-2160. All 3 substrates are insensitive to factor Xa but hydrolyzed to varying degrees by plasmin and trypsin. In contrast, S-2222 is sensitive to Xa and insensitive to thrombin. S-2251 is relatively plasmin-specific, being resistant to the clotting enzymes thrombin and Xa. S-2251 exhibits even greater sensitivity to the SK-plasmin complex than to plasmin. In addition, the substrate Chromozym PK (N-Bz-Pro-Phe-Arg-pNA, HCl) was evaluated and found to be relatively specific for plasma kallikrein. Assays for antithrombin III and heparin using S-2222 as the substrate and factor Xa as the enzyme, plasma plasminogen and plasmin inhibitors using S-2251 as the substrate, and plasma prekallikrein and kallikrein inhibitors using Chromozym PK as the substrate have been developed. Synthetic peptides mimicking amino acid sequences adjacent to proteolytic activation cleavage of plasma serine protease precursors appear to be sensitive and relatively specific tools applicable to kinetical and clinical studies of these enzymes and their inhibitors.
...
PMID:Serine protease specificity for peptide chromogenic substrates. 14 72

Hydrolysis with trypsin of citraconyl-carboxy-methyl-beta-galactosidase was carried out under limiting conditions. No Asp-Arg-X sequences were cleaved and many large peptides were produced. Butanol extraction from dilute acid proved very useful for separating the more hydrophobic fragments. Peptides were purified and sequenced. From this digest and two earlier preparations, all 80 theoretically possible tryptic fragments have been isolated and their structures determined.
...
PMID:Amino acid sequence of beta-galactosidase. VI. Limited tryptic digestion of the citraconylated protein and sequences of tryptic peptides. 14 95

We described previously the existence of a soluble ATPase activity in rat liver mitochondria [1]. The purification and catalytic properties have been described [2]. In a continuation of these experiments, we have studied the immunologic and structural properties of one molecular form of this enzyme : ATPase I. We have prepared the antiserum anti-ATPase I and demonstrated the purity of our enzyme preparation by immunodiffusion and immunoelectrophoresis. An immunohistochemical method also confirmed the localization of ATPase I in the soluble fraction of mitochondria. The molecular weight of ATPase I was measured by G 100 Sephadex gel filtration and was found to be 18,400; electrophoresis on polyacrylamide gels gave a value of 18,600. The pHi of ATPase I was found to be 7,2. Amino acid analysis showed high amounts of aspartic acid, glutamic acid, serine and glycine. The molecular weight calculated from the total amino acid residues was found to be 17,000. Alanine is the NH2 terminal amino acid. The peptide maps obtained after degrading ATPase I with cyanogen bromide or trypsin are in accordance with the methionine, lysine and arginine residues we found in the ATPase I molecule. ATPase I does not appear to be a glycoprotein.
...
PMID:Studies of soluble rat liver mitochondrial acid ATPases. II. Structural and immunological properties of ATPase 1. 15 69

The synthetic thrombin-inhibitor termed No. 205 (N-alpha-dansyl-L-arginine-4-ethyl-piperidine amide) found in our laboratories was studied kinetically using synthetic peptide substrates. The following results were obtained. 1. No. 205 inhibited thrombin competively with bz-Phe-Val-Arg-pNA and the Ki value obtained was extremely small, 3.7 x 10(-8) M. 2. No. 205 also inhibited trypsin competitively with bz-Phe-Val-Arg-pNA but the Ki value obtained was far larger than that for thrombin, 1.0 x 10(-5) M. 3. No. 205 inhibited F. Xa, plasmin and urokinase only to a small extent when estimated using 2 x 10(-4) M D-Val-Leu-Lys-pNA, bz-Ile-Glu-Gly-Arg-pNA and Glu-Gly-Arg-pNA, respectively. 4. No 205 differed from APPA in its specific inhibitory spectrum for thrombin as compared to trypsin, plasmin and F. Xa. The above results indicate that No. 205 is an extremely potent and highly selective reversible thrombin-inhibitor.
...
PMID:Kinetic studies on the selectivity of a synthetic thrombin-inhibitor using synthetic peptide substrates. 15 13

Two tryptic phosphopeptides containing the sites on the alpha and beta subunits of phosphorylase kinase which are phosphorylated by protein kinase, dependent on adenosine 3':5'-monophosphate (cyclic AMP), have been isolated and their amino acid sequences have been determined. 32P-labelled phosphorylase kinase, containing 1.9 mol phosphate per mol enzyme, was digested with an equimolar quantity of trypsin for 2.5 min at pH 7.0, 20 degrees C. This treatment released nearly all the 32P radioactivity associated with the beta subunit as trichloroacetic-acid-soluble material. Only a small proportion of the 32P radioactivity associated with the alpha subunit was solubilised, the remainder being removed in the trichloroacetic acid pellet. The beta-subunit tryptic phosphopeptide was completely resolved from traces of the alpha-subunit phosphopeptide by gel filtration on Sephadex G-25. Further purification by peptide mapping separated the phosphopeptide into four components, each derived from the same nine-amino-acid segment of the betachain, which was found to possess the sequence: Gln-Ser-Gly-Ser(P)-Val-Ile-Tyr-Pro-Leu-Lys. The four components were produced by the partial cyclisation of the N-terminal glutaminyl residue, and by the presence of two alleles for the beta subunit in the rabbit population, which led to a valine-isoleucine ambiguity. The alpha-subunit phosphopeptide was liberated from the trichloroacetic acid pellet by redigestion with trypsin. It was the largest component in the digest which remained soluble in 5% trichloroacetic acid, and obtained in a highly purified form by a single filtration on Sephadex G-50. The peptide comprised 39 amino acids of which nine were serine and three were threonine residues. Only one residue, the serine at position three from the amino terminus, was phosphorylated. The amino-terminal sequence of the peptide was shown to be: Arg-Leu-Ser(P)-Ile-Ser-Thr-Glu-Ser-Glx-Pro-Asx-Gly. The sequences confirm the stoichiometry of the reaction and the absolute specificity of cyclic-AMP-dependent protein kinase for just two of the 200 serine residues in the enzyme. These results and an inspection of the rate of phosphorylation of a number of skeletal muscle proteins, including each enzyme of the glycolytic pathway, lead to the conclusion that cyclic-AMP-dependent protein kinase is an extremely specific enzyme. The molecular basis of this specificity is discussed.
...
PMID:The hormonal control of activity of skeletal muscle phosphorylase kinase. Amino-acid sequences at the two sites of action of adenosine-3':5'-monophosphate-dependent protein kinase. 16 50

Trypsin- and thrombin-catalysed hydrolysis of the Nalpha-aryl-sulfonyl-L-arginine methyl esters was studied. Michaelis constants and kcat were determined. The hydrolysis of the substrates by trypsin appears to depend on the polar nature of substitutes. The thrombin- catalysed reaction was believed to be sensitive to steric effects of the introducted groups.
...
PMID:[Hydrolysis of the methyl esters of the N-arylsulfonyl derivatives of L-arginine by thrombin and trypsin]. 16 7


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---