Sequence determination of amino- and carboxyl-terminal residues of hypocalcemic protein TP extracted from bovine thymus gland.

Abstract

End group amino acid sequence was determined on a hypocalcemic protein TP1 purified from bovine thymus gland. Amino-terminal amino acid sequence was deduced to be His-Asx-Ala-Glx- by the dansyl-Edman degradation method. Carboxyl-terminal amino acid sequence was analyzed by digestion with carboxypeptidase A and Y, and it was deduced to be-Thr-Ala-Lys. Furthermore, the carboxyl-terminal amino acid was confirmed to be lysine alone by the hydrazinolysis method. According to these results and from previous data, it became apparent that TP1 did not bear the subunit structure, and it was clearly different from other hypocalcemic proteins obtained from bovine thymus and parotid gland.