A kinetic study of glucagon-like peptide-1 and glucagon-like peptide-2 truncation by dipeptidyl peptidase IV, in vitro.
In vivo inactivation of glucagon-like peptide-1 (GLP-1) and glucagon-like peptide-2 (GLP-2) was found to be associated with the proteolytic removal of their N-terminal dipeptide by the ectopeptidase dipeptidyl peptidase IV (DPP IV). Previous studies suggested that the in vivo metabolism of GLP-1 is much faster than that of GLP-2. In this paper, we investigated the in vitro truncation of GLP-2 and GLP-1 by DPP IV. The slower conversion rate observed for GLP-2 compared to GLP-1 was due to an approximately 10-fold reduction in catalytic rate constant. The selectivity of DPP IV for the glucagon-like peptides was compared with data obtained for other natural substrates using the same enzyme source in identical conditions.
Lambeir
Anne-Marie
AM
Laboratory of Medical Biochemistry, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1 S6, B-2610 Wilrijk, Belgium. anne-marie.lambeir@ua.ac.be
Proost
Paul
P
Scharpé
Simon
S
De Meester
Ingrid
I
D000595:Amino Acid Sequence; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism*; D005934:Glucagon / Q000378:metabolism*; D052216:Glucagon-Like Peptide 1; D053767:Glucagon-Like Peptide 2; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism*; D013997:Time Factors
D053767:Glucagon-Like Peptide 2; D010446:Peptide Fragments; D010455:Peptides; D011498:Protein Precursors; D052216:Glucagon-Like Peptide 1; D005934:Glucagon; D018819:Dipeptidyl Peptidase 4