06 February 2002
Cross-reacting determinant, Glycosyl-phosphatidylinositol, Glycosyl-Phosphatidylinositol anchor, Glycosyl-Phosphatidylinositol-specific phospholipase C, Inositol 1,2-cyclic monophosphate, Urinary dipeptidase
The release mechanism of the glycosyl-phosphatidylinositol (GPI)-anchored renal dipeptidase (EC 126.96.36.199) in vivo has been investigated. Triton X-114 phase separation indicated that the dipeptidase is exclusively present as a hydrophilic form in urine from porcine, rat, rabbit and human. Western blot analysis of human and porcine purified dipeptidase and the urine concentrates with anti-(cross-reacting determinant) serum demonstrated the presence of inositol 1,2-cyclic monophosphate indicating that the renal dipeptidase had been released from the membrane by the action of a phospholipase C. This is the first direct evidence for cleavage of a human GPI-anchored protein by a responsible phospholipase C in vivo.