Structure primaire de la caséine αS1 bovine.

Our earlier publications on the primary structure of bovine αs1 casein, which contains 198 amino acid residues in a single polypeptide chain, dealt with the sequence of forty-eight residues from the COOH-terminal and also with the various approaches utilized for the elucidation of the primary structure of the molecule: amino acid composition of tryptic peptides, composition and arrangement of the peptides obtained by selective hydrolysis at the arginyl or methionyl bonds and identification of the tryptic peptides in these two series of peptide fragments. In the present communication we report the sequence of sixty amino acid residues from the NH2-terminal of the bovine αs1 casein with the exception of a fragment consisting of seven amino in our final publication. The NH2-terminal of bovine αs1 casein contains markedly different zones which are successively basic (position 1 to 10), non-polar (position 20 to 33) and acid (position 45 to 60). We will report in another paper that the A variant of αs1 casein is characterized by a deletion of thirteen amino acid residues in the part of the NH2-terminal. [ABSTRACT FROM AUTHOR]