- Erratum in:
- FEBS Lett 2002 Feb 13;512(1-3):353.
Kinetic study of the processing by dipeptidyl-peptidase IV/CD26 of neuropeptides involved in pancreatic insulin secretion.
Laboratory of Medical Biochemistry, University of Antwerp, Belgium. lambeir@uia.ua.ac.be
Dipeptidyl-peptidase IV (DPPIV/CD26) metabolizes neuropeptides regulating insulin secretion. We studied the in vitro steady-state kinetics of DPPIV/CD26-mediated truncation of vasoactive intestinal peptide (VIP), pituitary adenylyl cyclase-activating peptide (PACAP27 and PACAP38), gastrin-releasing peptide (GRP) and neuropeptide Y (NPY). DPPIV/CD26 sequentially cleaves off two dipeptides of VIP, PACAP27, PACAP38 and GRP. GRP situates between the best DPPIV/CD26 substrates reported, comparable to NPY. Surprisingly, the C-terminal extension of PACAP38, distant from the scissile bond, improves both PACAP38 binding and turnover. Therefore, residues remote from the scissile bond can modulate DPPIV/CD26 substrate selectivity as well as residues flanking it.
PMID: 11696365 [PubMed - indexed for MEDLINE]