REDUCTION AND ALKYLATION OF HUMAN PLASMA OROSOMUCOID IN AQUEOUS SOLUTION AND IN 8 MUREA: A PHYSICOCHEMICAL AND IMMUNOCHEMICAL STUDY: HUMAN OROSOMUCOID: REDUCTION AND ALKYLATION

Abstract

Highly purified orosomucoid (α₁-acid glycoprotein) was exposed to mercaptoethanol, iodoacetamide and 8 M urea, in various combinations. The derivatives were examined by agar-gel electrophoresis, by acrylamide-gel "disc" electrophoresis (employing an improved method), by immunodiffusion techniques, and by quantitative immunochemical methods.The results indicated an —S—S— dependent tertiary structure for the polypeptide backbone, but one which could not be separated into subunits by the methods employed. The mechanisms of reduction and alkylation of the glycoprotein are discussed, and several alternate structural models for the polypeptide moiety are presented.