Inhibition of dipeptidyl peptidase IV (DP IV) by anti-DP IV antibodies and non-substrate X-X-Pro- oligopeptides ascertained by capillary electrophoresis.
Dipeptidyl peptidase IV (DP IV)-catalyzed hydrolysis of the NH2-X-Pro-containing N-terminal dodecapeptide of IL-2 was studied using free zone capillary electrophoresis as an alternative peptidase assay. In contrast to the conventional DP IV substrate glycyl-prolyl-p-nitroanilide (Gly-Pro-pNA), the hydrolysis of this peptide by DP IV was found to be significantly inhibited by anti-DP IV antibodies. Inhibition of DP IV was also observed with a number of non-substrate oligopeptides containing an N-terminal X-X-Pro- structure, including the HIV Tat protein. For Met-IL-2(1-6), we determined a competitive inhibition with an inhibition constant of ca. 100 microM.
Hoffmann
T
T
Center of Internal Medicine, Otto-von-Guericke University Magdeburg, Germany.
Reinhold
D
D
Kähne
T
T
Faust
J
J
Neubert
K
K
Frank
R
R
Ansorge
S
S
D000595:Amino Acid Sequence; D000906:Antibodies / Q000276:immunology* / Q000302:isolation & purification; D018819:Dipeptidyl Peptidase 4 / Q000276:immunology* / Q000378:metabolism; D019075:Electrophoresis, Capillary; D015696:Gene Products, tat / Q000276:immunology; D015699:HIV Envelope Protein gp120 / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism / Q000494:pharmacology
D000906:Antibodies; D015696:Gene Products, tat; D015699:HIV Envelope Protein gp120; D009842:Oligopeptides; D018819:Dipeptidyl Peptidase 4