Sequestration of pea reserve proteins by rough microsomes

Free polysomes, polysomes released from membranes, and rough microsomal vesicles isolated from developing cotyledons of Pisum sativum L. cv. Burpeeana were used to direct cell-free protein synthesis in a wheat germ system. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated that the polypeptide products had molecular weights ranging from 12,000 to 74,000. Some of the polypeptides migrated during electrophoresis with the same mobility as polypeptides present in legumin and vicilin preparations. By the use of rabbit antibodies raised against pea reserve proteins it was established that polysomes released from membranes and rough microsomes directed the synthesis of polypeptides that were related to reserve proteins whereas free polysomes did not.