title: The functional importance of the N-terminal region of human prolylcarboxypeptidase.
abstract: The renin-angiotensin-system cascade pathway generates the vasopressor and prothrombotic hormones, angiotensin II (Ang II) and angiotensin III (Ang III) from angiotensinogen. One of the key enzymes for the generation of angiotensin 1-7 (Ang 1-7) and angiotensin 2-7 (Ang 2-7) from Ang II and III, respectively, is prolylcarboxypeptidase (PRCP). To understand the contribution of the N-terminal region to catalysis, an N-terminal truncated form, lacking 179 N-terminal residues of PRCP (rPRCP(40)) was constructed. The circular dichroism (CD) spectrum of rPRCP(40) illustrated that it was structured with significant helical content as indicated by local minima at approximately 220 and 208nm. The main products of Ang III metabolized by rPRCP(40) were Ang 2-7 plus phenylalanine as determined by LC-MS. Angiotensin I (Ang I) blocked the metabolism of Ang III by rPRCP(40). These investigations showed that the C-terminal region of the rPRCP(40) contributes to PRCP's catalytic function, and provided additional experimental evidence for this suggestion.
authors.affiliation: Department of Pharmacology, University of Mississippi, 317 Faser Hall, University, MS 38677-1848, USA.
authors.forename: J
authors.initials: J
authors.lastname: Mallela
authors.forename: R
authors.initials: R
authors.lastname: Perkins
authors.forename: J
authors.initials: J
authors.lastname: Yang
authors.forename: S
authors.initials: S
authors.lastname: Pedigo
authors.forename: J M
authors.initials: JM
authors.lastname: Rimoldi
authors.forename: Z
authors.initials: Z
authors.lastname: Shariat-Madar
mesh_terms: D000803:Angiotensin I; D000804:Angiotensin II / Q000378:metabolism*; D000818:Animals; D002268:Carboxypeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002384:Catalysis; D002460:Cell Line; D004795:Enzyme Stability; D006801:Humans; D010446:Peptide Fragments / Q000378:metabolism*; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D010446:Peptide Fragments; D011994:Recombinant Proteins; C048187:angiotensin II (2-7); D000804:Angiotensin II; D000803:Angiotensin I; D002268:Carboxypeptidases; C022448:lysosomal Pro-X carboxypeptidase; C118790:angiotensin I (1-7)