Dipeptidyl peptidases 8 and 9: specificity and molecular characterization compared with dipeptidyl peptidase IV.
Dipeptidyl peptidases 8 and 9 have been identified as gene members of the S9b family of dipeptidyl peptidases. In the present paper, we report the characterization of recombinant dipeptidyl peptidases 8 and 9 using the baculovirus expression system. We have found that only the full-length variants of the two proteins can be expressed as active peptidases, which are 882 and 892 amino acids in length for dipeptidyl peptidase 8 and 9 respectively. We show further that the purified proteins are active dimers and that they show similar Michaelis-Menten kinetics and substrate specificity. Both cleave the peptide hormones glucagon-like peptide-1, glucagon-like peptide-2, neuropeptide Y and peptide YY with marked kinetic differences compared with dipeptidyl peptidase IV. Inhibition of dipeptidyl peptidases IV, 8 and 9 using the well-known dipeptidyl peptidase IV inhibitor valine pyrrolidide resulted in similar K(i) values, indicating that this inhibitor is non-selective for any of the three dipeptidyl peptidases.
Bjelke
Jais R
JR
Protein Structure and Biophysics, Novo Nordisk A/S, Novo Allé, 2880 Bagsvaerd, Denmark.
Christensen
Jesper
J
Nielsen
Per F
PF
Branner
Sven
S
Kanstrup
Anders B
AB
Wagtmann
Nicolai
N
Rasmussen
Hanne B
HB
D000595:Amino Acid Sequence; D016367:Baculoviridae / Q000235:genetics / Q000378:metabolism; D002850:Chromatography, Gel; D004150:Dipeptidases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D018819:Dipeptidyl Peptidase 4 / Q000737:chemistry* / Q000378:metabolism; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D020836:Protein Structure, Quaternary; D011758:Pyrroles / Q000378:metabolism / Q000494:pharmacology; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity; D014633:Valine / Q000378:metabolism / Q000494:pharmacology
D004791:Enzyme Inhibitors; D010446:Peptide Fragments; D011758:Pyrroles; D011994:Recombinant Proteins; C112092:valine-pyrrolidide; D004150:Dipeptidases; C471241:DPP9 protein, human; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; C487997:DPP8 protein, human; D018819:Dipeptidyl Peptidase 4; D014633:Valine