title: Identification of gp108, a pathogenic antigen of passive Heymann nephritis, as dipeptidyl peptidase IV.
abstract: Our previous paper showed that the glycoprotein of Mr 108,000 (gp108) 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.
mesh_terms: D000818:Animals; D001324:Autoantigens / Q000302:isolation & purification*; D001327:Autoimmune Diseases / Q000276:immunology*; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D018819:Dipeptidyl Peptidase 4; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000276:immunology*; D005921:Glomerulonephritis / Q000276:immunology*; D007684:Kidney Tubules / Q000276:immunology*; D008871:Microvilli / Q000276:immunology; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D001324:Autoantigens; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; D018819:Dipeptidyl Peptidase 4