Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.11 (CD10)
 9,792 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Unlike the pancreatic endopeptidase zymogens, procarboxypeptidase A is activated very slowly in vitro. The activation proceeds through the removal of about 100 amino acids away from the N-terminus of the chain. The cleavage of the susceptible bond(s) in monomeric and aggregated forms of bovine procarboxypeptidase A by catalytic amounts of trypsin was found to be very fast. However, as in the case of the porcine zymogen, the expression of the carboxypeptidase activity was considerably delayed by the inhibitory effect of the activation peptide which remains bound to the enzyme molecule after the trypsin treatment of the zymogen. alpha-Carboxypeptidase A was mainly formed under the relatively mild conditions used, indicating that the Arg-1-Ala+1 bond is probably the first to be cleaved during in vitro activation. The bovine carboxypeptidase activity was immediately and reversibly expressed upon dimethylmaleylation of the activation mixtures. This expression does not require full dissociation of the enzyme-peptide complex but merely a suitable change in its quaternary structure resulting from a modification of some electrostatic interactions upon dimethylmaleylation. Separation of bovine carboxypeptidase A from its activation peptide was only achieved upon filtration of the dimethylmaleylated mixtures in the presence of 6 M urea. The bovine activation peptide contains at least 93 amino acids compared to the 94 amino acids found by other authors for the rat and porcine peptides and sequencing of the first 53 amino acids showed a 75-85% homology with the latter two peptides.
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PMID:Further studies on the activation of bovine pancreatic procarboxypeptidase A by trypsin. 360 14

Different forms of D-beta-hydroxybutyrate dehydrogenase were submitted to various proteases in order to get information on enzyme molecular structure and on phospholipid -enzyme interaction. Except for leucinaminopeptidase, all proteases tested inactivated the phospholipid-free enzyme, while no inactivation was observed with the lecithin-enzyme complex. However, non-reactivating phospholipid gave very poor protection against proteases. After endopeptidase treatment, a new band of 25,000 Mr appeared instead of the 32,000 Mr band (apodehydrogenase). Surprisingly, the so-called protected form of the enzyme (lecithin-complex) was also proteolysed while still enzymatically active. Carboxypeptidase A inactivated quite thoroughly the enzyme although the 32,000 Mr band appeared unaffected. These results demonstrate that the configuration of the phospholipid-free apodehydrogenase is quite vulnerable to most proteases, in contrast to the configuration of the lecithin-complexed enzyme. The N-terminal end is probably blocked while the C-terminal end looks quite important for enzymatic activity.
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PMID:Limited proteolysis of D-beta-hydroxybutyrate dehydrogenase: relationships between phospholipid-protein interactions and catalytical activity. 638 1