Subunit Structure and Composition of Oat Seed Globulin

Abstract

Oat (Avena sadva L.) seed globuln was extracted from pound cary-opses with 1 M NaCI, 0.05 M Tris(hydroxymethyl)antnoethane (pH 8.5) at room temperature. The globulin had a sedimentation constant of 12.1, and a molecular weight of 322,000, as determined by analytical ultracentrifu-gation. The globulin could be separated into two major subunits by sodium-dodecyl sulfate polyacrylamide gel electropboresis. Molecular weights of the subunits were 21,700 (a) and 31,700 (p8), and they were present in equimolar amounts. A subunit model of 6a and 6p8 per molecule of globulin is proposed. Amino acid analysis ilndicated that the a subunit contained