Isolation of alpha, beta, and gamma conglycinins

Abstract

Alpha, beta, and gamma conglycinins are soybean globulins which together with glycinin constitute the major components of the reserve proteins of soybean seeds ( Glycine max). These proteins were isolated by fractionation procedures based on Bio-Gel A-1.5m and Sephadex G-100 gel filtration, and DEAE-Sephadex chromatography. The isolated conglycinins were found to be homogeneous by immunoelectrophoresis in agar gel, disc electrophoresis, and disc immunoelectrophoresis. The antisera used for their identification were an anti-soybean water extract serum 123 and a monospecific anti-γ-conglycinin serum 130. In addition, a monospecific anti-glycinin serum 102 was used to detect possible contamination of conglycinin preparations by glycinin. The identity of α-conglycinin with a 2S soybean globulin component, β-conglycinin with the major component of a crude 7S soybean protein preparation, and γ-conglycinin with the major component of another crude 7S soybean protein preparation is discussed.