1aye
|
HUMAN PROCARBOXYPEPTIDASE A2
OverviewOverview
The three-dimensional structure of human procarboxypeptidase A2 has been, determined using X-ray crystallography at 1.8 A resolution. This is the, first detailed structural report of a human pancreatic carboxypeptidase, and of its zymogen. Human procarboxypeptidase A2 is formed by a, pro-segment of 96 residues, which inhibits the enzyme, and a, carboxypeptidase moiety of 305 residues. The pro-enzyme maintains the, general fold when compared with other non-human counterparts. The globular, part of the pro-segment docks into the enzyme moiety and shields the S2-S4, substrate binding sites, promoting inhibition. Interestingly, important, differences are found in the pro-segment which allow the identification of, the structural determinants of the diverse activation behaviours of, procarboxypeptidases A1, B and A2, particularly of the latter. The, benzylsuccinic inhibitor is able to diffuse into the active site of, procarboxypeptidase A2 in the crystals. The structure of the, zymogen-inhibitor complex has been solved at 2.2 A resolution. The, inhibitor enters the active site through a channel formed at the interface, between the pro-segment and the enzyme regions and interacts with, important elements of the active site. The derived structural features, explain the intrinsic activity of A1/A2 pro-enzymes for small substrates.
About this StructureAbout this Structure
1AYE is a Single protein structure of sequence from Homo sapiens with as ligand. Active as Carboxypeptidase A2, with EC number 3.4.17.15 Known structural/functional Site: . Full crystallographic information is available from OCA.
ReferenceReference
The three-dimensional structure of human procarboxypeptidase A2. Deciphering the basis of the inhibition, activation and intrinsic activity of the zymogen., Garcia-Saez I, Reverter D, Vendrell J, Aviles FX, Coll M, EMBO J. 1997 Dec 1;16(23):6906-13. PMID:9384570
Page seeded by OCA on Sun Feb 3 09:32:06 2008