Identification of dipeptidyl peptidase IV as the antigen of a monoclonal anti-prostasome antibody

✍ Scribed by Sabine P. Schrimpf; Ulf Hellman; Lena Carlsson; Anders Larsson; Gunnar Ronquist; B. Ove Nilsson

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 150 KB
• Volume: 38
• Category: Article
• ISSN: 0270-4137
• DOI: 10.1002/(sici)1097-0045(19990101)38:1<35::aid-pros4>3.0.co;2-j

✦ Synopsis

Background:

Our purpose was to elucidate the identity of an antigen of a monoclonal antibody against prostasomes, which are prostate-derived organelles occurring freely in human semen.

Methods:

Monoclonal antibodies against prostasomes were generated by intrasplenic immunization to allow better characterization of the prostasomes. one third of the resulting antibodies bound to a 110-kda prostasomal protein on western blots.

Results:

The antigen was purified from seminal prostasomes by anion exchange chromatography and gel electrophoresis. after in-gel digestion and amino-acid sequence analysis of selected peptides, it was identified as dipeptidyl peptidase iv (dpp iv), ec 3.4.14.5, also known as t-cell-activating antigen cd26. no dpp iv could be detected in the supernatant obtained after preparative ultracentrifugation of the prostasomes.

Conclusions:

Dpp iv/cd26 is structurally bound to prostasomes rather than being free in seminal fluid. this enzyme may play a critical role in the promoting effect of prostasomes on forward motility of spermatozoa.