抄録
The dinitrofluorobenzene method has been applied to the identification and quanti-tative determination of the N-terminal amino acid of M-PhAB-TAA. It was shown that alanine was a sole N-terminal amino acid.
The carboxypeptidase technique has been applied for the characterization of the C-terminal group of the modified enzyme and it was supposed that the C-terminal region of M-PhAB-TAA was changed by proteolysis.
The amino acid composition of the modifi-ed enzyme has been determined by chromato-graphic techniques on columns of Amberlite IR-120. Separate determination has been made for tryptophan by colorimetric analysis using p-dimethylaminobenzaldehyde.
From these results, the best estimation for the amino acid residues of M-PhAB-TAA was made and compared its side chain groups with those of PhAB-TAA.
The author is grateful to Prof. S. Akabori and Prof. K. Narita for their kind guidances for this investigation. Thakns are also due to Sankyo Co., Ltd. for their kind supply of “Takadiastase Sankyo”.
