Purification and determination of the modifying protein responsible for the post-synthetic modification of creatine kinase (EC 2.7.3.2) and enolase(EC 4.2.1.11)

Abstract

The purification of a serum protein, responsible for the postsynthetic modification of CK and enolase, is described. A purification of about 1 300-fold could be reached after subsequent chromatography of human serum on DEAE cellulose and Sephacryl S-200 Superfine followed by affinity chromatography using antibodies against human serum albumin, C3 and C4 and against total human serum proteins. A recovery of 160% of modifying activity was found. The molecular mass and the isoelectric point of the modifying protein have been determined. It is concluded that the concentration of the modifying protein in human serum is < 210 mg/1.