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:3.5.1.4 (deaminase)
5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A series of acetyl-peptidyl-amides containing the amino acid sequence around the Arg-Ser kallikrein cleavage site of bovine kininogen were synthesized and tested for their ability to inhibit both the kinin-releasing activity and the amidase activity of purified human urinary kallikrein. The substrate analogues were competitive inhibitors for human urinary kallikrein and the heptapeptides (P4-P3'), hexapeptides (P3-P3'), and pentapeptides (P2-P3') gave Ki values of 140, 64, and 18 microM respectively, while the tetrapeptides (P1-P3'), tripeptides (P1'-P3') and dipeptides (P2'-P3') had little or no inhibitory activity. The effective analogues had neither kinin-like nor kinin-blocking activity on the rat uterus either before or after exposure to human urinary kallikrein. The effective human urinary kallikrein inhibitors were further examined for their effect on other serine proteases, including human plasma kallikrein, plasmin, complement components (C1s, C1r), bovine coagulation factors (IIa, IXa, and Xa), elastase, and trypsin. These peptides showed little inhibition of the circulating serine proteases but yielded a Ki for the nonspecific protease trypsin in the microM range. These results should provide the basis for the development of highly specific tissue kallikrein inhibitors to aid in elucidating the in vivo role(s) of tissue kallikreins.
...
PMID:Specificity of substrate analogue inhibitors of human urinary kallikrein. 384 67

Human urinary active kallikrein and prokallikrein were separated on DEAE-cellulose and octyl-Sepharose columns and both purified to homogeneity by affinity chromatography, gel filtration and hydrophobic h.p.l.c. Prokallikrein was monitored during purification by trypsin activation followed by determination of both amidase and kininogenase activity. After trypsin activation, purified prokallikrein had a specific kininogenase activity of 39.4 micrograms of bradykinin equivalent/min per mg and amidase activity of 16.5 mumol/min per mg with D-Val-Leu-Arg-7-amino-4-trifluoromethylcoumarin. Purified active kallikrein had a specific activity of 47 micrograms of bradykinin/min per mg. The molecular mass of prokallikrein was 48 kDa on electrophoresis and 53 kDa on gel filtration whereas active kallikrein gave values of 46 kDa and 53 kDa respectively. Antisera to active and prokallikrein were obtained. In double immunodiffusion and immunoelectrophoresis, antiserum to active kallikrein reacted with active and pro-kallikrein. Antiserum to prokallikrein contained antibodies to determinants not found in active kallikrein, presumably due to the presence of the activation peptide in the proenzyme. Human prokallikrein can be activated by thermolysin, trypsin and human plasma kallikrein. Activation of 50% of the prokallikrein (1.35 microM) was achieved in 30 min with 25 nM-thermolysin, 78 nM-trypsin or 180 nM-human plasma kallikrein. Thus thermolysin was the most effective activator. Thermolysin activated prokallikrein by releasing active kallikrein with N-terminal Ile1-Val2. Thus human tissue (glandular) prokallikrein can be activated by two types of enzymes: serine proteinases, which cleave at the C-terminus of basic amino acids, and by a metalloproteinase that cleaves at the N-terminus of hydrophobic amino acids.
...
PMID:Purification of human urinary prokallikrein. Identification of the site of activation by the metalloproteinase thermolysin. 393 23

The alpha-2 macroglobulins from human serum and plasma were isolated by Bio-Gel P-300 and A5m gel filtration. The material showed a single peak on sedimentation velocity ultracentrifugation, a mol wt of 650,000 by sedimentation equilibrium ultracentrifugation, and a major precipitin arc in the alpha-2 macroglobulin region by immunoelectrophoresis against whole human serum. Two bands were observed in the alpha-2 macroglobulin region when acrylamide gel electrophoresis was performed with a pH 8.9 running gel. When a pH 7.8 gel was used, five electrophoretic species were observed. In both cases, the preaddition of stoichiometric amounts of trypsin or chymotrypsin added to alpha-2 macroglobulin resulted in disappearance of slower bands leaving only one band on acrylamide gel electrophoresis patterns. Preparative acrylamide gel electrophoresis separated alpha-2 macroglobulin obtained from Bio-Gel into five closely-spaced species. Separation was sufficiently adequate to show that those species of alpha-2 macroglobulin which bound trypsin and chymotrypsin were represented by slower moving species and that the fastest moving material had lost virtually all of the ability to bind these enzymes. Preparative acrylamide gel electrophoresis of a mixture of alpha-2 macroglobulin-trypsin complex and alpha-2 macroglobulin revealed that the fast moving component was alpha-2 macroglobulin-trypsin complex and that the slower moving material was unbound alpha-2 macroglobulin. The naturally occurring amidase activity of the alpha-2 macroglobulin using benzoylarginine-p-nitroanilide (BAPNA) as substrate was investigated and unlike its trypsin-binding activity, amidase activity was found to be of the same specific activity in all electrophoretic fractions. Binding of trypsin and chymotrypsin to alpha-2 macroglobulin revealed that alpha-2 macroglobulin maximally bound 2 moles of trypsin and 1 mole of chymotrypsin. When the enzymes were added simultaneously there was competition. Chymotrypsin added to alpha-2 macroglobulin before the addition of trypsin prevented all trypsin binding even though only one site was filled with chymotrypsin. These results were explained by the acrylamide gels which showed that 1 mole of chymotrypsin was sufficient to convert all the alpha-2 macroglobulin to a species with the fastest mobility which no longer binds additional enzyme.
...
PMID:The separation of alpha-2 macroglobulin into five components with differing electrophoretic and enzyme-binding properties. 410 93

A simple and specific method for the estimation of trypsin in human duodenal juice was described. The procedures are as follows: add 10 ul of undiluted sample, measure 2.0 ml of substrate solution of benzoylarginine p-nitroanilide (BAPNA) 0.5 mg/ml in a Tris buffer, incubate at 37 degrees C for 10 minutes, then terminate tryptic activity with 2.0 ml of 30% v/v acetic acid, and read absorbance at 410 nm by a spectrophotometer. Coexistence of bile pigments, chymotrypsin or elastase did not interfere the estimation of tryptic activity in duodenal juice. Reproducibility (both within- and between-assay variances less than 8%), recovery (mean of 100%) and stability of the enzyme activity after 3 weeks at -20 degrees C with glycerol (96% of the initial activity) were sufficient for clinical use. The amidase activity of trypsin estimated with BAPNA as substrate correlated well both to the esterase activity measured with p-toluenesulfonyl-L-arginine methyl ester (TAME) as substrate and to the immunoreactivity determined by radioimmunoassay in human duodenal juice. Good correlation between total outputs of amylase and trypsin were observed in 29 patients undergoing pancreozymin secretin test. The present assay technique will provide simple and reliable means of measuring trypsin in duodenal fluid and of mutual checks of the secretory capacity of pancreatic enzymes and will increase diagnostic accuracy of pancreozymin secretin test.
...
PMID:A simple and specific determination of trypsin in human duodenal juice. 615 4

A canine model of bile-induced pancreatitis has been employed to investigate time-dependent changes in the molecular forms of trypsin in blood and ascitic fluid in this disease. The distribution of immunoreactive trypsin as trypsinogen and trypsin bound to plasma inhibitors in ascitic fluid and plasma during the course of the disease has been investigated by means of a radioimmunoassay for canine pancreatic cationic trypsin. In addition, trypsinlike amidase activity was determined in plasma and ascitic fluid using Z-Gly-Gly-Arg-beta-Nap as substrate. Early plasma and ascitic fluid samples in four dogs that died contained primarily trypsinogen, while extensive activation of trypsinogen to alpha 2-macroglobulin and alpha 1-protease inhibitor-bound trypsin occurred in the course of the disease. A fifth dog survived and showed little activation of trypsinogen. In the four dogs that died, the levels of trypsinlike amidase activity in the ascitic fluid were substantial throughout the course of the disease. The plasma levels of trypsinlike activity in these animals were much lower, but increased during the disease process. The dog that survived had lower concentrations of trypsinlike activity in ascitic fluid and plasma. These results suggest that activation of trypsinogen resulting in inhibitor-bound forms of trypsin in ascitic fluid and plasma is important in the pathogenesis of acute pancreatitis.
...
PMID:Immunoreactive forms of cationic trypsin in plasma and ascitic fluid of dogs in experimental pancreatitis. 617 Feb 31

Two classes of inhibitors of trypsin (ED 3.4.21.4) have been studied, viz. active site-directed agents such as ovomucoid and active site titrants such as 4-methylumbelliferyl-4-guanidinobenzoate. The kinetics of beta-naphthyl-amidase inhibition by an active site-directed agent were markedly different from simultaneous assays of the availability of the active site towards active site titrants in the presence of the active site-directed agents. Analysis of these data indicated an exchange of active site-directed agent by subsequent addition of active site titrant. One class of trypsin inhibitor could be displaced by another from the trypsin active centre. Competitive chase experiments were designed to measure this exchange in which the active site-directed agent was first equilibrated with trypsin, then partially displaced by incremental additions of an active site titrant; the degree of active sites occupied by these two agents was then determined by active site titration with a second reagent.
...
PMID:Evidence for exchange of inhibitors which bind to the active site of trypsin. Displacement of one inhibitor with a competitive inhibitor. 617 54

It was found that the effect of heparin on the amidase activity of urokinase (E C 3.4.21.31), plasmin (E C 3.4.21.7) and trypsin (E C 3.4.21.4) depended on the substrate used. No effect of heparin on the amidase activity of urokinase and trypsin was observed when Pyro Glu-Gly-Arg-p-nitroanilide (S-2444) and alpha-N-acetyl-L-lysine-p-nitroanilide (ALNA) were used as substrates. Heparin acted as a uncompetitive inhibitor of trypsin (Ki = 1.2 X 10(-6) M), plasmin (Ki = 4.9 X 10(-6) M) and urokinase (Ki = 1.0 X 10(-7) M) when Bz-Phe-Val-Arg-p-nitroanilide (S-2160), H-D-Val-Leu-Lys-p-nitroanilide (S-2251) and plasminogen, respectively, were used as substrates. These results, as well as the data obtained by studying the effect of the simultaneous presence of heparin and competitive inhibitors suggest that although heparin is not bound at the active center of these enzymes, it may influence the effectivity of catalysis.
...
PMID:Kinetic study of the effect of heparin on the amidase activity of trypsin, plasmin and urokinase. 622 10

A new fluorogenic substrate for serine proteinases, bis(N-benzyloxycarbonyl-L-argininamido)Rhodamine [(Cbz-Arg-NH)2-Rhodamine], was synthesized, purified and chemically and enzymically characterized. This compound, which employs Rhodamine as a fluorophoric leaving group, is the first in a series of substrates designed to measure the amidase activity of proteinases. Cleavage of one of the amide bonds of (Cbz-Arg-NH)2-Rhodamine by a trypsin-like serine proteinase converts the non-fluorescent bisamide substrate into a highly fluorescent monoamide product. Significant differences in the electronic absorption and fluorescence emission spectra and quantum yields of bis-, mono- and un-substituted Rhodamine are reported. Macroscopic kinetic constants for the interaction of (Cbz-Arg-NH)2-Rhodamine with bovine trypsin, human and dog plasmin and human thrombin were determined. Compared with the corresponding 7-amino-4-methylcoumarin-based analogue, (Cbz-Arg-NH)2-Rhodamine exhibits an increase in sensitivity with these enzymes of 50--300-fold. The physical basis for this increase in sensitivity is discussed.
...
PMID:Rhodamine-based compounds as fluorogenic substrates for serine proteinases. 634 11

The amino acid sequence of deoxycytidylate deaminase isolated from T2 phage-infected Escherichia coli has been determined. The enzyme is a hexamer, consisting of identical polypeptide subunits, each composed of 188 amino acids with a calculated Mr = 20,560. The primary structure was established by automatic Edman degradation of the intact carboxymethylated protein and of peptides derived from the protein by cleavage with cyanogen bromide, trypsin, chymotrypsin, the Staphylococcus aureus V8 protease, and 2-(2-nitrophenylsulfenyl)-3-methyl-3-bromoindolenine. Knowledge of the primary structure of deoxycytidylate deaminase should aid in determining the allosteric binding site of the negative effector, dTTP, recently reported (Maley, F., and Maley, G.F. (1982) J. Biol. Chem. 257, 11876-11878), and eventually that of the enzyme's positive regulator, dCTP, as well as its substrate. The deaminase has been crystallized through the use of polyethylene glycol; a scanning electron micrograph is presented.
...
PMID:Complete amino acid sequence of an allosteric enzyme, T2 bacteriophage deoxycytidylate deaminase. 634 41

It was shown that the plasminogen activator inhibitor, ZGlyGlyArgCH2Cl, inactivates the kininogenase and plasminogen activator activities in the whole human granulocyte lysate and human granulocyte proteinase fractions isolated by isoelectrofocusing from the granulocyte lysate (pH 3-10). The kinetics of irreversible inhibition of the ZGlyGlyArgpNA-amidase activity in granulocyte proteinase fractions (pI 10.75, 8.9 and 8.3) by ZGlyGlyArgCH2Cl was measured. These data confirm the earlier obtained results on the trypsin-like nature of the human granulocyte plasminogen activator and its identity to this cell kininogenase.
...
PMID:[Identity of kininogenase and plasminogen activators in human granulocytes]. 642 31


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

---