The Complete Amino‐Acid Sequence of Hen Ovalbumin

Abstract

The complete amino acid sequence of hen ovalbumin, comprising 385 residues, was determined. The sequence was deduced from the 17 CNBr fragments and from peptides derived by digestion with proteolytic enzymes. The MW of the polypeptide chain of ovalbumin is 42,699. Ovalbumin has 4 sites of postsynthetic modification; in addition to the acetylated N terminus, the carbohydrate moiety is located at Asn-292, and the 2 phosphorylated serines are at residues 68 and 344. The signal sequence of ovalbumin is between residues 234 and 252. The heptapeptide released during the conversion of ovalbumin to plakalbumin by subtilisin digestion corresponds to residues 346-352. The hen ovalbumin polymorphism characterized by an Asn .fwdarw. Asp replacement results from a mutation at residue 311. The amino acid sequence of ovalbumin deduced from these amino acid sequence studies is in complete agreement with the sequence of mRNA determined by McReynolds et al.