Dipeptidyl peptidases 8 and 9: specificity and molecular characterization compared with dipeptidyl peptidase IV.

TY - JOUR

T1 - Dipeptidyl peptidases 8 and 9: specificity and molecular characterization compared with dipeptidyl peptidase IV.

AU - Bjelke, Jais R

AU - Christensen, Jesper

AU - Nielsen, Per F

AU - Branner, Sven

AU - Kanstrup, Anders B

AU - Wagtmann, Nicolai

AU - Rasmussen, Hanne B

N1 - Keywords: Amino Acid Sequence; Antigens, CD26; Baculoviridae; Chromatography, Gel; Dipeptidases; Dipeptidyl Peptidases; Enzyme Activation; Enzyme Inhibitors; Humans; Kinetics; Molecular Sequence Data; Peptide Fragments; Protein Structure, Quaternary; Pyrroles; Recombinant Proteins; Sequence Alignment; Substrate Specificity; Valine

PY - 2006

Y1 - 2006

N2 - 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.

AB - 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.

U2 - 10.1042/BJ20060079

DO - 10.1042/BJ20060079

M3 - Journal article

C2 - 16475979

SN - 0264-6021

VL - 396

SP - 391

EP - 399

JO - Biochemical Journal

JF - Biochemical Journal

IS - 2

ER -