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)

To clarify the properties and functions of a trypsin inhibitor from Japanese barley in comparison with the inhibitor from Pirkka barley, an inhibitor was isolated from the barley Hordeum distichum L var. emend Lamark by extraction with 1% NaCl, ammonium sulfate fractionation and repeated chromatography on DEAE-cellulose and CM-cellulose. The final purified preparation of the inhibitor was found to be homogeneous by both chromatographic and electrophoretic analysis. The inhibitor was thermostable and was stable over the broad pH range from 2 to 11. No inhibition was observed by heavy metal ions and many reagents at 10(-2) M, except that p-chloromercuribenzoate caused a 69% loss of activity. The inhibitor was subjected to isoelectric focusing at pH 7.51 and its molecular weight was calculated to be 14,200+/-900 by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The apparent dissociation constant for the complex between the inhibitor and trypsin[EC 3.4.21.4] was 1.64 X 10(-7)M with casein as a substrate. One microgram of purified inhibitor inhibited 1.5 mug of pure trypsin in the hydrolysis of alpha-N-benzoyl-DL-arginine-p-nitroanilide. By chemical modification of arginyl residues in the inhibitor with 1,2-cyclohexanedione, the inhibitor was shown to be an arginine inhibitor. The inhibitor contained relatively many basic amino acids and few half cystines as compared with Pirkka barley trypsin inhibitor.
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PMID:Studies on trypsin inhibitor in barley. I. Purification and some properties. 0 Mar 80

The inhibitory effect of dioctyl sodium sulfosuccinate on the proteolytic activity of trypsin was investigate over the pH 6-8 range. The antitryptic activity was determined using two different substrates: casein and N,alpha-benzoyl-DL-arginine-p-nitroanilide hydrochloride. The mechanistic studies revealed the substrate-inhibitor interaction to be the overall major mechanism of inhibition. This interaction was shown to involve substrate depletion, probably involving some primary sites of the natural substrate casein. Some inhibition was also shown to be due to an interaction between the enzyme and the inhibitior molecules. The interactions of the inhibitor with the enzyme and the substrate were irreversible. The possible therapeutic significance of the inhibitory effect of the surfactant is discussed.
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PMID:Inhibitory effect of dioctyl sodium sulfosuccinate on trypsin activity. 0 Apr 84

The extracts of granules of human polymorphonuclear leukocytes hydrolyzed a variety of proteins including human and bovine hemoglobin, human fibrinogen, human and bovine serum albumin, bovine elastin, and casein. The hydrolysis of all the proteins except fibrinogen and elastin was increased by addition of urea. Various inhibitors of trypsin, kallikrein, plasmin, Clr, Cls, and other proteolytic enzymes had no inhibitory effect. Slight inhibition was observed with polyanethol sulfonate and strong inhibition with normal human serum. Serum of patients with hereditary angioneurotic edema having no functional C1-esterase inhibitor was as effective in inhibiting the proteolysis as normal serum. The inhibitor was localized in 4S fractions of normal serum fractionated on Sephadex G-200. Fractionation of normal serum by ammonium sulfate precipitation, Sephadex G-200 filtration, and CM-Sephadex chromatography did not result in appearance of inhibitory activity in more than one protein peak, suggesting the possibility that only one inhibitor might be responsible. Since all fractions which contained the inhibitor of proteolysis also contained alpha1-antitrypsin, since sera of patients having low alpha1-antitrypsin levels contained less inhibitory activity, and since antibodies against alpha1-antitrypsin reversed the inhibition obtained from normal serum, the inhibition of proteolysis may be attributed to alpha1-antitrypsin.
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PMID:Some properties of proteolysis by polymorphonuclear leukocyte-granule extracts. 0 49

Immobilized trypsin and alpha-chymotrypsin were obtained as a result of the enzyme attachment to bromo-cyanogen activated cepharose. Proteolytic activity (substrate--casein) of immobilized trypsin and alpha-chymotrypsin was 18.7 and 9%, respectively and their esterase activity with methyl ester benzoyl-L-arginine (trypsin) and ethyl ester acetyl-L-tyrosine (alpha-chymotrypsin) was 75 and 20% of that of soluble enzymes. Immobilized enzymes were used to purify proteinase inhibitors from potatoes by affine chromatography. Specific activity of trypsin and chymotrypsin inhibitors was increased 10 and 6 times, respectively. By isoelectric focussing it was shown that the purified preparation of chymotrypsin inhibitors consisted of two acid proteins and one alkaline protein, the latter being in predominance. The purified preparation of trypsin inhibitors contained equal amounts of proteins with the isoelectric point at pH 7.1 and 8.9 and a low quantity of the component with the isoelectric point at pH 5.7.
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PMID:[Properties of immobilized trypsin and alpha-chymotrypsin and their use for purification of proteinase inhibitors from potatoes]. 0 33

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

Two acid proteases, one hydrolysing hemoglobin and the other hydrolysing benzoyl arginine naphthyamide (BANA), were separated and partially purified from human skin buffer extract. The acid protease hydrolysing hemoglobin was purified about 190 fold by Sephadex G-100 gel filtration and DEAE-cellulose chromatography. It hydrolysed hemoglobin at pH 3.5, casein at pH 5.8 and skin protein substrate at pH 6.0. It did not markedly hydrolyse synthetic protease substrates. The molecular size of this protease was 38000. The protease was insensitive to common protease modifiers and closely resembles cathepsin D purified from other organs. The BANA-hydrolysing acid protease was purified about 760 fold by Sephadex G-100 gel filtration and affinity chromatography on organomercurial Sepharose 4B gel. It preferentially hydrolysed BAEE, BANA and BAA with an optimum at pH 5.8. The hydrolysis of BAPA, LeuNA and protein substrates was very low. This acid protease was found to be highly dependent on reducing agents, as DTT, and chelating agents, as EDTA, and was inhibited by pCMB and TLCK. The molecular size of the enzyme was 28000. This protease closely resembles cathepsin B1 purified from other organs. Human skin was also shown to contain a low activity of benzoyl arginine amide (BAA) hydrolysing acid protease with a molecular size of about 50000 and resembling cathepsin B2. Human skin contained an inhibitor with a molecular size of about 13000 against human skin cathepsin B1. This inhibitor did not inhibit trypsin, chymotrypsin or skin proteases other than cathepsin B1.
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PMID:Human skin proteases. Separation and characterization of two acid proteases resembling cathepsin B1 and cathepsin D and of an inhibitor of cathepsin B1. 0 17

Psoriatic scale proteases were found to be extracted effectively in salt solution (1 mol/l) containing Triton X-100 (5 g/l). The extraction in dilute buffer or sucrose yielded low activities. The acid (0.25 N H2SO4) and KSCN (2 mol/l) solutions effectively extracted plasminogen activator. Fibrinolysin was most active in salt (1 mol/l KCl) and in KSCN (2 mol/l) extracts. Psoriatic scale proteases were fractionated by Sephadex G-100 gel filtration and further by DEAE cellulose chromatography. Five different enzyme preparations were obtained. The first preparation, resembling cathepsin D, effectively hydrolysed hemoglobin at pH 3.5 and casein at pH 5.8 and was insensitive to protease modifiers. The second preparation effectively hydrolysed trypsin substrates (AGLME, TAME, BAEE and BANA) and also histone and casein at pH 7.2 and was inhibited by protease inhibitors, TLCK and E-600. The third preparation hydrolysed histone and casein at pH 10.2 and was effectively inhibited by E-600 and partially by protease inhibitors and TPCK. The fourth preparation, resembling cathepsin B1, hydrolysed BANA and BAEE at pH 5.8 and was activated by SH-reagents and EDTA. The fifth enzyme preparation hydrolysed ATEE and was inhibited by E-600 and TPCK. Plasminogen activator was found mainly in the second enzyme preparation and fibrinolysin activity in the third and fifth enzyme preparations. The second, third and fifth enzyme preparations were different from the enzymes found in healthy human skin. The proteases of psoriatic scale resemble those of tissue and cell cultures undergoing rapid cell division. The possible role of proteases in the increased cell division in psoriasis plaque is discussed.
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PMID:Human skin proteases. Fractionation of psoriasis scale proteases and separation of a plasminogen activator and a histone hydrolysing protease. 0 31

The anionic tryptic enzyme from the crayfish (crayfish trypsin) was adsorbed to DEAE-Sephadex A-50 and covalently coupled to BrCN-activated Sepharose 4B and porous glass loaded with isothiocyanate propyl groups (ITC-glass). The relative activities against p-tosylarginine methyl ester (TosArgOMe) were found to be 30 to 100% for DEAE-Sephadex crayfish trypsin, 20 to 53% for Sepharose crayfish trypsin, and 17 to 38% for ITC-glass crayfish trypsin. The relative activities rise with declining protein content of the enzyme matrix complexes. The highest relative proteinase activities (substrate: 1% casein) were obtained with Sepharose crayfish trypsin (74%), followed by DEAE-Sephadex crayfish trypsin (68%) and ITC-glass crayfish trypsin (45%). Similar results are obtained with protamine and native lactate dehydrogenase as substrates. In accordance with the Sepharose bovine trypsin complex the apparent Michaelis constant (Km(app)) of the Sepharose crayfish trypsin with TosArgOMe was found to be markedly higher than that of the native enzyme. The pH-activity profiles of the crayfish trypsin derivatives using TosArgOMe as substrate were shown to be displaced towards more alkaline pH values by 0.5 (ITC-glass crayfish trypsin) and 1 (Sepharose crayfish trypsin) pH units, respectively, or towards more acidic pH values (by 1.5 pH units) with the polycationic derivative (DEAE-Sephadex crayfish trypsin) as compared to the native enzyme (optimum pH 8.6). Concerning the temperature stability of the derivatives, Sepharose crayfish trypsin was more stabile, ITC-glass crayfish trypsin behaves like the native crayfish trypsin, and DEAE-Sephadex crayfish trypsin was more sensitive at elevated temperatures as compared to the soluble enzyme. The properties of the crayfish trypsin derivatives are compared with the properties of the bovine analogues.
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PMID:[Preparation and some properties of immobilized trypsin from the crayfish Cambarus affinis Say (author's transl)]. 0 51

The protease isolated jawasee shrub was found to hydrolyze egg albumin, casein, haemoglobin and gelatin optimally near neutral pH. Fibrin, bovin serum albumin, skin albumin and skin mucoids were hydrolyzed at slightly alkaline pH, while skin globulins were hydrolyzed at slightly acidic pH. The enzyme had no effect of fibrous collagen. The optimum conditions for the hydrolysis of 50 mg of egg albumin were found to be 50 mg of alhagain at pH 6.0 and 45 degrees C for 30 minutes. A Km value of 4.4 X 10(-3) M was obtained from the Lineweaver-Burk plot for the hydrolysis of egg albumin. The enzyme was found to be comparatively thermostable and was most stable at pH 4.7. Ultraviolet irradiation exhibited no appreciable effect on the enzyme activity. The ultraviolet absorption spectrum of alhagain in bi-distilled water resembles those of bromelain and trypsin. The sugar-containing enzyme was found to have a molecular weight of 20,650. The enzymeconsists of 189 amino acid residues per molecule, neutral and acidic amino acids being present in high concentrations. The partial specific volume of alhagain was calculated to be 0.743 ml/g from its amino acid composition. Phenylalnine and arginine formed the amino terminal amino acids of alhagain, while aspartic acid and serine were identified as its carboxy terminal amino acids. Results are discussed with relation to other plant proteases.
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PMID:Studies on the physico-chemical properties of alhagain. 2 Nov 47

An extracellular protease from Myxococcus virescens was purified by phosphate precipitation, gel exclusion, and ion-exchange chromatography. The enzyme appeared homogeneous upon disc electrophoresis. The molecular weight of the protease was estimated to be 26,000. The enzyme was rapidly inactivated by ethylenediaminetetraacetate, but the activity could be partially restored by divalent cations. Diisopropylphosphorofluoridate inhibited enzyme activity completely. Michaelis-Menten kinetics were obeyed with casein and hemoglobin as substrates. First-order kinetics were obtained with elastin as the substrate, provided trypsin was in excess. Petidolytic activity indicated that the peptide bonds hydrolyzed by the enzyme were mainly those involving amino acids with nonpolar side chains.
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PMID:Purification and properties of an extracellular protease from Myxococcus virescens. 2 36


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