Identification of gp108, a pathogenic antigen of passive Heymann nephritis, as dipeptidyl peptidase IV
Natori, Y.; Hayakawa, I.; Shibata, S.
Clinical and Experimental Immunology 70(2): 434-439
1987
ISSN/ISBN: 0009-9104 PMID: 2892601 Document Number: 305194
Our previous paper showed that the glycoprotein of Mr 108,000 (gp 108) is one of the major components of rat renal tubular brush border antigens and that an injection of anti-gp108 antiserum in rats induces passive Heymann nephritis with acute and severe proteinuria. In this study, gp108 was identified as a monomer of dipeptidyl peptidase IV (DPP IV). The anti-gp108 antibody was shown to immunoprecipitate DPP IV from Triton-extract of renal tubular membrane fractions. DPP IV was co-purified with gp108 from the Triton-extract by columns of DEAE-cellulose and Bio-gel-A-1.5 m. The ratio of DPP IV activity and gp108 content was nearly constant throughout the purification steps. The final purified gp108 showed a high specific activity of DPP IV, comparable to that reported for purified rat DPP IV. These results indicate that gp108 is a monomer of DPP IV.