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. Trypsin, at different concentrations, significantly inhibited lysine absorption (P less than 0.05) in a dose-dependent pattern. 2. Maximum inhibition equivalent to 35% below control value was reached with 10 micrograms/ml (100 BAEE units) trypsin with a non-reversible inhibitory effect. 3. Chymotrypsin at 10 micrograms/ml produced a significant decrease (P less than 0.05) of lysine absorption although it did not exceed 5%. Perfusion of both enzymes did not show an additive inhibitory effect. 4. Lysine absorption showed a 39% decrease with 10 micrograms/ml trypsin and 1 X 10(-4) M ouabain, whereas ouabain alone produced 34% inhibition. 5. Lysine absorption showed a 71% decrease with 10 micrograms/ml trypsin in a sodium-free medium, and 70% inhibition with Na-free medium alone. 6. The inhibition of lysine absorption after trypsin treatment could be due to inhibition of the active component of lysine transport.
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PMID:Enzymatic inhibition of lysine transport across the small intestine in vivo. 289 17

Tissue plasminogen activator was treated with Sepharose-bound trypsin or chymotrypsin. Trypsin rapidly converted the one-chain activator to the two-chain form. This caused a marked increase in the amidolytic activity, while plasminogen activation initially increased but then decreased again. SDS/polyacrylamide gel electrophoresis in combination with [3H]diisopropylfluorophosphate active-site labeling revealed that after the conversion to the two-chain activator a minor cleavage occurred in the B chain, while the A chain was substantially degraded. Chymotrypsin caused a marked decrease in both amidolytic activity and plasminogen activation. SDS/polyacrylamide gel electrophoresis under reducing conditions revealed that two pairs of new bands had appeared, with Mr or about 50,000/52,000 and 17,000/20,000 respectively. N-terminal sequence analysis identified cleavage sites at peptide bonds 420-421 and 423-424. These bonds are located in a region of the activator which is homologues to the segments of trypsin and chymotrypsin, where autocatalytic cleavages occur during their activations. However, treatment of two-chain activator with chymotrypsin had markedly less effect on plasminogen activation and amidolytic activity. By treatment of samples of chymotrypsin-digested one-chain activator with plasmin, amidolytic activity could be largely restored. Thus, chymotrypsin may, by cleaving bonds 420-421 and 423-424, convert the active one-chain activator into an 'inactive' zymogen, which is again 'activated' by plasmin cleavage.
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PMID:Proteolytically induced variations in the enzymatic properties of tissue plasminogen activator. Activations, inactivations and reactivations. 294 92

The authors report the effects of four proteases (trypsin, plasmin, chymotrypsin and thrombin) on human heart adenylate cyclase (HHAC) activity. Trypsin and plasmin inhibited HHAC at concentrations higher than 0.3 and 1 microgram/ml, respectively. Chymotrypsin had a biphasic effect, with a stimulation (from 0.5 to 10 micrograms/ml) followed by an inhibition at higher concentrations. Maximal stimulation was obtained at 3 micrograms/ml and averaged 67.2 +/- 5.4%. Thrombin had no significant effect at concentrations up to 1 mg/ml. These data indicate that proteases might regulate HHAC and therefore influence cardiac function.
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PMID:The effects of trypsin, plasmin, chymotrypsin and thrombin on human heart adenylate cyclase activity. 295 13

Chymotrypsin in NaCl medium at low ionic strength rapidly cleaves a bond in the N-terminal half of the alpha-subunit of pure membrane-bound (Na+ + K+)-ATPase from outer renal medulla. Secondary cleavage is very slow and the alpha-subunit can be converted almost quantitatively to a 78 kDa fragment. The sensitive bond is exposed to cleavage when the protein is stabilized in the E1 form by binding of Na+ or nucleotides. The bond is protected in medium containing KCl (E2K form), but it is exposed when ADP or ATP are added (E1KATP form). Fluorescence analysis and examination of ligand binding and enzymatic properties of the cleaved protein demonstrate that cleavage of the bond stabilizes the protein in the E1 form with sites for tight binding of nucleotides and cations exposed to the medium. About two 86Rb ions are bound per cleaved alpha-subunit with normal affinity (Kd = 9 microM). The bound Rb+ is not displaced by ATP or ADP. The nucleotide-potassium antagonism is abolished and ATP is bound with high affinity both in NaCl and in KCl media. Na+-dependent phosphorylation is quantitatively recovered in the 78 kDa fragment, but the affinity for binding of [48V]vanadate is very low after cleavage. ADP-ATP exchange is stimulated 4-5-fold by cleavage; while nucleotide dependent Na+-Na+, K+-K+, or Na+-K+ exchange are abolished. Cleavage with chymotrypsin in NaCl at the N-terminal side of the phosphorylated residue thus stabilizes the E1 form of the protein and abolishes cation exchange and conformational transitions in the protein although binding of cations, nucleotides and phosphate is preserved. In contrast, cleavage with trypsin in KCl at the C-terminal side of the phosphorylated residue does not interfere with E1-E2 transitions and Na+-Na+ or K+-K+ exchange. This data support the notion that cation exchange and E1-E2 transitions are thightly coupled.
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PMID:Chymotryptic cleavage of alpha-subunit in E1-forms of renal (Na+ + K+)-ATPase: effects on enzymatic properties, ligand binding and cation exchange. 299 72

The primary structure of the Hypoderma lineatum collagenase was determined. Chymotrypsin digestion and thermolysin fragmentation of the chymotryptic core gave 30 and 5 peptides, respectively, accounting for all the residues of the protein. These peptides were aligned with overlapping peptides derived from tryptic and Staphylococcus aureus V8 proteinase digests. Hypoderma collagenase is a serine proteinase composed of 230 amino acids (Mr 25,223). It displays a high degree of sequential homology with the serine proteinases of the trypsin family, especially with another collagenolytic enzyme, the proteinase I of the crab Uca pugilator. The six half-cystinyl residues of Hypoderma collagenase correspond to 6 of the 10 half-cystinyl residues of chymotrypsin, and the residues forming the charge-relay system of the active site of chymotrypsin (His-57, Asp-102, and Ser-195) are found in corresponding regions. The prediction of the secondary structure of the collagenase is given.
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PMID:Complete amino acid sequence of the collagenase from the insect Hypoderma lineatum. 303 99

Digestion of the rat liver glucocorticoid receptor with chymotrypsin results in the generation of a 42-kDa fragment which contains the steroid-binding and DNA-binding domains and the antigenic site for the BuGR anti-glucocorticoid receptor monoclonal antibody, while digestion with trypsin generates a 15-kDa receptor fragment containing only the DNA-binding function and the BuGR epitope (Eisen, L.P., Reichman, M.E., Thompson, E.B., Gametchu, B., Harrison, R. W., and Eisen, H.J. (1985) J. Biol. Chem. 260, 11805-11810). In this paper, glucocorticoid receptor of mouse L cells that were grown in the presence of [32P]orthophosphate was digested with trypsin or chymotrypsin (either before or after immune purification with BuGR antibody) and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, autoradiography, and Western blotting. The receptor is endogenously phosphorylated only on serine residues. Chymotrypsin digestion results in a 32P-labeled 42-kDa receptor fragment which contains steroid-binding, DNA-binding, and BuGR-reactive sites. Trypsin digestion generates a 27-kDa steroid-bound fragment (meroreceptor) which is not labeled with 32P and a 32P-labeled 15-kDa fragment which contains both the DNA-binding domain and the BuGR epitope. We have calculated that there are 4 times as many phosphate residues in the intact receptor than in the 42-kDa chymotrypsin fragment. From examination of 32P-labeled receptor fragments, we have deduced that one phosphate is located between amino acids 398 and 447, a region containing the BuGR epitope and about one-third of the DNA-binding domain, and the remaining three phosphates appear to be clustered just to the amino-terminal side of the BuGR epitope in a region defined by amino acids 313 to 369. Treatment of intact 32P-labeled receptor in cytosol with alkaline phosphatase removes these three phosphates, but it does not remove the phosphate from the DNA-binding-BuGR-reactive fragment and it does not affect the ability of the transformed receptor to bind to DNA-cellulose.
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PMID:Localization of phosphorylation sites with respect to the functional domains of the mouse L cell glucocorticoid receptor. 304 15

An inhibitor of the UDP-N-acetylgalactosamine:GM3, N-acetylgalactosaminyltransferase (EC 2.4.1.92) has been purified close to 100-fold from chicken blood serum. The method of purification includes heating, dialysis, passage through a column of DEAE-Sephadex, filtration through Amicon XM 100, and passage through Sepharose 6B. The molecular weight determined by Sepharose 6B was 200,000, but on sodium dodecyl sulfate-polyacrylamide gel electrophoresis it appears as if the compound dissociated into components of 68,000. The inhibitor was not active on other glycosyl transferases and lost its inhibitory activity following treatment with pronase and trypsin. alpha-Chymotrypsin did not affect the inhibitor. An antibody to this inhibitor was prepared which decreased its inhibitory capability and precipitated with it in a radial double immunodiffusion experiment.
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PMID:An inhibitor of the UDP-N-acetylgalactosamine:GM3, N-acetylgalactosaminyltransferase: purification and properties, and preparation of an antibody to this inhibitor. 313 81

Proteolytic digestion and indirect immunostaining were used to compare the platelet and sarcoplasmic reticulum Ca2+-ATPase proteins. When the platelet and sarcoplasmic reticulum Ca2+-ATPase proteins were digested in the native state with trypsin, the platelet Ca2+-ATPase, which had an apparent undigested molecular mass of 103 kDa, yielded 78-kDa and 25-kDa fragments. Calcium transport activity depended on the integrity of the 103-kDa protein, while the digested protein had residual ATPase activity. Tryptic digestion of the sarcoplasmic reticulum pump protein, which also had an undigested molecular mass of 103 kDa, yielded products with apparent molecular masses of 55 kDa, 36 kDa, and 26 kDa. Distinct patterns were also observed when the platelet and sarcoplasmic reticulum calcium pump proteins were digested with chymotrypsin and Staphylococcus aureus protease in the presence of sodium dodecyl sulfate. Chymotrypsin digestion of the platelet protein resulted in the appearance of products with apparent molecular masses of 70 kDa, 39 kDa, and 31 kDa, while a similar digestion of the sarcoplasmic reticulum calcium pump protein yielded 54-kDa, 52.5-kDa, 46-kDa, 41-kDa, and 36-kDa fragments. Exposure of the sarcoplasmic reticulum and platelet Ca2+-ATPase proteins to S. aureus protease also yielded dissimilar fragmentation patterns. These results indicate that the Ca2+-ATPases from platelets and sarcoplasmic reticulum are distinct proteins.
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PMID:Evidence that platelet and skeletal sarcoplasmic reticulum Ca2+-ATPase are structurally distinct. 316 Jun 95

Chymotrypsin can completely solubilize insoluble [3H]-labeled ligamentum nuchae elastin. At similar enzyme levels, trypsin solubilizes only 5% of the elastin substrate whereas pancreatic elastase completely solubilizes the elastin at one-tenth the concentration required for chymotrypsin solubilization. The elastolytic activity of chymotrypsin is dependent on Ca+2, is enhanced by SDS, and is inhibited by NaCl at concentrations above 10 mM. The elastolytic activity of chymotrypsin is also inhibited by TPCK, a chymotrypsin specific inhibitor, but not by TLCK, a trypsin specific inhibitor. Neither TPCK nor TLCK abolish the elastolytic activity of pancreatic elastase. The sizes of [3H]elastin fragments produced by the elastolytic activity of chymotrypsin are similar to those produced by pancreatic elastase, and larger than those produced by trypsin.
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PMID:Studies on the elastolytic activity of chymotrypsin. 316 94

Elastase, V8 protease, subtilisin, trypsin, and chymotrypsin all cleaved the 1462-residue polypeptide of rat carbamyl phosphate synthetase I in segment C 160-180 residues from the COOH-end. Its activator N-acetylglutamate (AcGlu) increased the rate of cleavage approximately ninefold, presumably by binding preferentially to the conformation in which C is exposed. ATP/Mg2+ prevented proteolysis both +/- AcGlu. Kd,app for AcGlu (66 microM) and ATP (4.2 microM with AcGlu and 5 mM Mg2+) was estimated from the pseudo-first-order rate constants for inactivation caused by cleavage with elastase at C. Chymotrypsin and trypsin also hydrolyzed the enzyme, independent of AcGlu, at site D within less than 20 residues of the COOH-end. D was protected by ATP only in the presence of AcGlu and K+, and enzyme hydrolyzed exclusively at D had greater than 30-fold higher Km's for AcGlu and ATP. Digestion by trypsin at a third site (B) approximately 530 residues upstream from C appeared to occur subsequent to hydrolysis at C. Slow cleavage by elastase at an additional site (A) to give 360- and 1100-residue peptides was unaffected by AcGlu and ATP, and caused only modest loss of activity. These peptides were isolated by chromatography on DEAE-cellulose. Assignment of the smaller one to the NH2-end on the basis of its cysteine content places site A in the junction between the segments homologous to the small glutaminase and large synthetase subunits of Escherichia coli carbamyl phosphate synthetase II. Neither peptide alone was active; maximal regain of activity (approximately 25%) occurred on combining them in equimolar proportions. The sizes of the peptides produced by further digestion of the site A digest gave the approximate locations of the other sites. Sites A (Ala-417) and B (Arg-787) have recently been identified by NH2-terminal sequencing (S. G. Powers-Lee and K. Corina (1986) J. Biol. Chem. 261, 15349-15352). Reasons for the low value of KAcGlu,app are examined, and protection by ATP is discussed in relation to previous models for the conformational equilibria of the enzyme.
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PMID:Proteolysis as a probe of ligand-associated conformational changes in rat carbamyl phosphate synthetase I. 328 64


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