Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cellulose acetate electrophoresis (pH 8,6 ionic strength 0,05) puts in evidence the soluble complexes "albumin-protamine" which are easily distinguished from albumin being more positively charged. The albumin-protamine complexes formed in serum or plasma, after addition of protamine, undergo in vitro a dissociation progressing with time to the complete restitution of albumin. This dissociation is slowed down by the inhibitors of the carboxypeptidase B (SCPB), an enzyme present in plasma and serum, but is not influenced by the inhibitor phenylmethyl-sulfonyl fluoride (PMSF). A protamine which had lost its four C-terminal arginines by the action of a DFP-treated carboxypeptidase B (CPB) still formed complexes with albumin (and, besides, remained able to neutralize heparin). On the contrary protamine degraded first by CPB, and afterwards by the DFP-treated carboxypeptidase A (CPA) lost these two properties. These results suggest that the dissociation of albumin-protamine complex in plasma and serum requires a protaminase action additional to the action of SCPB.
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PMID:[Protaminase activity of plasma and serum in vitro. II.- Electrophoretic study of serum albumin-protamine soluble complexes]. 670 Oct 6

The activation peptide of the monomeric procarboxypeptidase A from porcine pancreas was isolated by means of controlled trypsin digestion of the proenzyme followed by ion-exchange chromatography under dissociating conditions (7 M urea). The molecular weight of the isolated peptide was estimated to be around 11500-12000 (corresponding to approx. 100-103 residues) as judged by SDS electrophoresis and amino acid analysis, a figure that agrees with the differences between the corresponding values for procarboxypeptidase A and carboxypeptidase A (peptidyl-L-amino acid hydrolase, EC 3.4.17.1). The activation peptide has a high content of hydrophobic and acidic amino acids, and lacks cysteine. A remarkable feature is the strong competitive inhibitory action of the peptide on both porcine and bovine pancreatic carboxypeptidase A activity, with a Ki in the nanomolar range, and its null ability to inhibit porcine pancreatic carboxypeptidase B (EC 3.4.17.2). The above properties, and the fact that the peptide has the same N-terminal residue (lysine) as the parent procarboxypeptidase A, suggest that the isolated peptide contains most (if not all) of the activation segment of the proenzyme.
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PMID:The severed activation segment of porcine pancreatic procarboxypeptidase A is a powerful inhibitor of the active enzyme. Isolation and characterisation of the activation peptide. 713 80

The effect of terbium (Tb) on the protease activity in pancreas of mice was studied. Administration of Tb at doses of 20 and 200 mumol/kg increased the activities of trypsin and carboxypeptidase A, but did not affect the activities of chymotrypsin and carboxypeptidase B. High Tb concentrations were found in the liver and spleen compared to the kidney and pancreas. Increases in Ca concentrations in the pancreas, kidney, and spleen after Tb administration were observed. The pancreatic slice experiments showed the increase in trypsin activity after Tb treatment and increases in trypsin and carboxypeptidase A after Ca treatment. Tb inhibited strongly the activities of authentic chymotrypsin and carboxypeptidase A. These results suggest that the increase in trypsin activity in the pancreas after Tb administration results from the activation of trypsinogen by Tb and Ca ions and that the increase in carboxypeptidase A activity is due to the activation of procarboxypeptidase A by trypsin and Ca ion, which increased after Tb administration.
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PMID:Effect of terbium on protease activity in pancreas of mice. 799 67

The observation of binding synergism has been successfully extended to include carboxypeptidases A and B. The behaviour of these two enzymes follows the same pattern previously found for three other Zn-proteases. Thus in all cases examined, the affinity of a suitable Zn-ligand is increased in the presence of a compound (specificity probe) which contains the key structural features of specific substrates. A bifunctional ligand such as phosphonoacetate is particularly useful for generating synergism in both carboxypeptidases. Presumably the carboxylate moiety binds to the C-terminal recognition site while the other functional group interacts with the metal ion. Several basic compounds (e.g. methyl guanidine) act as effective specificity probes for carboxypeptidase B while phenol and other hydrophobic substances serve this purpose in carboxypeptidase A. The above phenomenon appears to be a mechanism designed to enhance catalytic efficiency through a substrate-induced conformational change. We postulate that there is a requirement for at least one ionizable group at the active site. The proposed mechanism keeps this group in the correct ionization state in the presence of water and increases its reactivity after exclusion of water by substrate binding. We suggest the term xerophilic shift for this process. Since proton transfer is a common process in enzyme reactions, the xerophilic-shift mechanism may play a similar role in many instances. It should therefore be possible to detect binding synergism in a wide variety of enzymes.
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PMID:General occurrence of binding synergism in zinc proteases and its possible significance. 826 43

We have established the peptidase content of a P2 fraction (enriched in synaptosomes) and plasma membranes prepared from canine intestinal mucosa. Fourteen exo- and endopeptidases were assayed with fluorimetric or chromogenic substrates and identified by means of specific peptidase inhibitors. Post-proline dipeptidyl aminopeptidase IV, aminopeptidase M, and carboxypeptidase A were the most abundant exopeptidases, while aminopeptidases A and B, dipeptidyl aminopeptidase, pyroglutamyl peptide hydrolase I, and carboxypeptidase B displayed little, if any, activity. Endopeptidase 24.11 was the only endopeptidase that was detected in high amount. By contrast, proline endopeptidase exhibited a low activity, while angiotensin-converting enzyme, endopeptidase 24.15, endopeptidase 24.16, and cathepsin B and D-like activities were not detected. The catabolic rates of the two related neuropeptides, neurotensin (NT) and neuromedin N (NN), established that NN was inactivated 16 to 24 times faster than NT by plasma membrane and P2 fractions, respectively. Furthermore, the two peptides underwent qualitatively distinct mechanisms of degradation. A phosphoramidon-sensitive formation of NT(1-10) was detected as the major NT catabolite, indicating that NT was susceptible to an endoproteolytic cleavage elicited by endopeptidase 24.11. By contrast, NN was inactivated by the action of an exopeptidase at its N-terminus, leading to the formation of [des-Lys1]NN. The occurrence of this NN metabolite was prevented by bestatin and actinonin, but not by the aminopeptidase B inhibitor, arphamenine B, indicating that the release of the N-terminal residue of NN was likely due to aminopeptidase M.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differential catabolic fate of neuromedin N and neurotensin in the canine intestinal mucosa. 833 46

The objective of this research was to formulate a mixture of commercial proteases that would mimic the rate and extent of protein degradation obtained using strained ruminal fluid. The proteolytic activity of strained ruminal fluid and several commercial proteases was characterized using 13 L-amino acid p-nitroanilides as artificial substrates. A mixture of Streptomyces griseus protease, chymotrypsin, and proteinase K at .042, 2.5, and .5 enzyme units/mL, respectively, was similar to the activity of strained ruminal fluid against the same artificial substrates. However, degradative activities were different in incubations with feed proteins as substrates. The rates of degradation of expeller soybean meal, solvent soybean meal, and casein were .08, .05, and .08/h, respectively, using the enzyme mixture and .03, .15, and .24/h using strained ruminal fluid. A second experiment compared degradative activity of S. griseus protease at .066 enzyme units/mL, ficin at .5 enzyme units/mL, and a mixture of trypsin, carboxypeptidase B, chymotrypsin, and carboxypeptidase A at 116.6, .5, 2.5, and .5 enzyme units/mL, respectively. Protein degradation rates obtained with strained ruminal fluid were two to six times faster than those obtained with the enzyme mixtures. A third experiment compared the degradability of 15 feed proteins with the mixture of trypsin, carboxypeptidase B, chymotrypsin and carboxypeptidase A to that with strained ruminal fluid. Degradation rates obtained using strained ruminal fluid ranged from .007 to .217/h; degradation rates using the enzyme mixture ranged from .010 to .079/h and were lower (P = .004) than with strained ruminal fluid. Overall, the experiments indicated that the commercial enzymes tested did not mimic the protein degradative activity of strained ruminal fluid.
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PMID:Characterization of the proteolytic activity of commercial proteases and strained ruminal fluid. 870 28

The effect of nickel (Ni) on the enzymatic activities in the pancreas of mice was studied. Administration of Ni at the dose of 5 mg Ni/kg increased the trypsin activity and decreased carboxypeptidase A activity, but did not affect the activities of chymotrypsin, carboxypeptidase B, amylase, and lipase. Increases in Ca concentrations in the pancreas after Ni administration were observed. In the pancreatic slice experiments, Ni treatment showed a slight decrease in trypsin activity and remarkable decreases in chymotrypsin and carboxypeptidase A activities, and Ca treatment induced increases in the activities of trypsin and carboxypeptidase A. These results suggest that the increase in trypsin activity in the pancreas after Ni administration results from the activation of trypsinogen by the Ca ion and that the decrease in carboxypeptidase A activity is based on the inhibitory effect of Ni on carboxypeptidase A activity.
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PMID:Effect of nickel on enzymatic activities in the mouse pancreas. 877 77

Crotamine, a basic, myonecrotic, histamine-releasing neurotoxin, was isolated from Crotalus durissus terrificus venom. Carboxypeptidase A was shown to be activated by crotamine when acting upon N-carbobenzoxyglycil-L-phenylalanine. However the activity of carboxypeptidase B upon the substrate hippuryl-L-arginine was not enhanced by this toxin. Teh basic histamine releasers protamine and compound 48/80 also activated carboxypeptidase A. These three agents activated both alpha-chymotrypsin when acting upon acetyl-L-tyrosine ethyl ester and also five snake venom phospholipase-like myotoxins acting upon egg yolk phosphatidylcholine. These findings suggest that the action of these agents during histamine release may involve the participation of specific intermediary hydrolases which, upon activation, would enhance their cytolytic effects on the sequence of events which lead to granule extrusion and histamine release from mast cells.
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PMID:The histamine releasers crotamine, protamine and compound 48/80 activate specific proteases and phospholipases A2. 930 35

Extracts prepared from Antarctic krill (Euphausia superba), mainly consisting of acidic proteolytic enzymes, have been studied with capillary electrophoretic techniques. Approximately 50 repeatable peaks were obtained with capillary zone electrophoresis on an untreated fused-silica capillary using a phosphate buffer containing anionic and cationic fluorosurfactant additives as separation medium. A faster separation was achieved on a polyvinyl alcohol coated capillary. Quantitative variations of individual proteins regarding different krill enzyme batches were noted. In the krill samples trypsin-like serine proteinase, carboxypeptidase A and carboxypeptidase B were tentatively identified.
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PMID:Separation of proteolytic enzymes originating from Antarctic krill (Euphausia superba) by capillary electrophoresis. 952 59

The secretion of zinc and the level of carboxypeptidase A and B activity in pancreatic juice were studied in three pigs fitted with a pancreatic pouch re-entrant cannula (PM pigs) and three different pigs with a catheter surgically implanted in their pancreatic duct (CM pigs). The zinc in the pancreatic juice appeared to be primarily associated with carboxypeptidase A and B. Both the concentration of zinc in pancreatic juice and the daily secretion of zinc in PM pigs were greater than in CM pigs. However, compared to the daily intake of zinc, its secretion in pancreatic juice was low. The specific activity levels of carboxypeptidase A and B in pancreatic juice collected from PM pigs were higher than in CM pigs. The total activity of carboxypeptidase A in pancreatic juice did not differ between collection methods. The total activity of carboxypeptidase B was higher in pancreatic juice collected from PM than from CM pigs. The differences in zinc and carboxypeptidase secretion between PM and CM pigs were probably due to physiological changes induced following the different surgical preparations of the animals.
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PMID:Pancreatic secretion of zinc and carboxypeptidase A and B in growing pigs. 979 83


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