Amino Acid Composition of Rice Prolamin Polypeptides

Abstract

Rice prolamin extracted with 60% (v/v) n-propanol from protein-rich rice bran was fractionated into individual polypeptides by SDS-polyacrylamide gel electrophoresis and isoelectric focusing. The prolamin polypeptides of 10, 13, and 16 kDa were acid hydrolized, and the amino acid composition of each polypcptide was analyzed. These prolamin polypeptides were rich in glutamic acid/glutamine and leucine but poor in lysine as reported previously for prolamins of many cereals. The 10 and 16 kDa polypeptides had a markedly high content of sulfur-containing amino acids.