Cleavage of atrial natriuretic peptide by a kidney membrane-bound carboxypeptidase A.
An enzymatic activity that cleaved the C-terminal Tyr of ANP (1-28) was characterized in human kidney microvillar membranes by using 125I-labeled rat ANP as substrate. This activity was inhibited by potato carboxypeptidase inhibitor (PCI) and 1.10 phenanthroline, suggesting that it corresponded to a metallo-carboxypeptidase. Solubilization experiments indicated that the carboxypeptidase activity could be recovered in the supernatant after 1% Triton X-100 extraction. As separation by ion exchange chromatography revealed several peaks of enzyme activity, PCI coupled to Sepharose was used for purification. This step resulted in a single protein band at 30 kDa, as analyzed by SDS-PAGE.
Michel
A
A
Laboratoire de Chimie Biologique, Université de Mons-Hainaut, Mons, Belgium.
Nortier
J
J
Humblet
A
A
Paradis
C
C
De Prez
E
E
Deschodt-Lanckman
M
M
D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D002268:Carboxypeptidases / Q000378:metabolism*; D043422:Carboxypeptidases A; D002847:Chromatography, Agarose; D006801:Humans; D007457:Iodine Radioisotopes; D007672:Kidney Cortex / Q000378:metabolism* / Q000648:ultrastructure; D008871:Microvilli / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology; D012995:Solubility
D007457:Iodine Radioisotopes; D011480:Protease Inhibitors; D009320:Atrial Natriuretic Factor; D002268:Carboxypeptidases; D043422:Carboxypeptidases A