The primary structure of the major parvalbumin from hake muscle. Overlapping peptides obtained with chemical and enzymatic methods. The complete amino-acid sequence.

Abstract

Work on the amino acid sequence of the major parvalbumin from hake muscle has been pursued with the aim of obtaining large fragments and overlapping peptides permitting the tryptic peptides sequenced previously to be ordered and the structure of the N‐terminal portion of the molecule to be established.Cyanogen‐bromide cleavage at the single methionine and tryptic digestion limited to the single arginine after maleylation were found useful in this respect and, with the help of the previous data, allowed the last 44 residues of the molecule to be placed unambiguously.Additional information was obtained from a chymotryptic digest of the protein which resulted in almost complete elucidation of the sequence of the first 24 residues and valuable knowledge on two other fragments, 12 and 29‐residues long, respectively.Application of both limited and extensive peptic‐digestion, the first one supplemented with the diagonal technique for cysteine peptides, permitted the remaining gaps to be filled, yielding an unique sequence of 108 residues now in full agreement with the amino acid composition of the protein.The location of the three amide groups of this parvalbumin is described and completes the description of its primary structure.