Serum proteins with NAD+ glycohydrolase activity and anti-CD38 reactivity--elevated levels in serum of tumour patients.

Abstract

NAD(+) glycohydrolase activities in serum samples from cancer patients were two-to three-fold higher than the activities in samples from healthy controls. SDS-PAGE analysis of serum samples followed by Western blotting revealed the presence of two proteins of similar to 45 and similar to 21 kDa that were immunoreactive with human CD38-specific monoclonal antibodies T16, HIT2 and OKT10. These proteins appeared to be more abundant in serum from cancer patients. NAD(+) glycohydrolase activity in serum could be enriched by immunoaffinity chromatography by using T16-Sepharose 4B. The results suggest that the relative abundance of proteins immunologically related to CD38 may account for the elevated levels of glycohydrolase activities in serum of tumour patients. (C) 1998 Elsevier Science Ireland Ltd.