Renaturation of Soybean 11S Globulin

Abstract

Renaturation of soybean 11S globulin was carried out by dialysis against 0.035 m phosphate buffer (pH 7.6) containing 0.4 m NaCl starting from denatured states in 8 m urea solution either in the presence or absence of 0.2 m 2-mercaptoethanol. The yield of the renatured 11S globulin was 70 % from the denatured state as judged by gel filtration. The purified renatured 11S globulin from the denatured state was found to be identical with the native protein when judged from gel chromatographic, immunological, ultracentrifugal, gel electrophoretic and circular dichroic analyses, as well as by studies of subunit composition and of susceptibility to proteolytic digestion. On the other hand, the renaturation of 11S globulin from the reductively denatured state yielded a protein which was somewhat different from the native protein as judged from gel electrophoretic and circular dichroic analyses, and also by studies of subunit composition and of susceptibility to proteolytic digestion.