Buffalo α S1-casein; its terminal residues and amino acid composition

Summary BuffaloaS₁-casein was treated with carboxypeptidase-A to determine the C-terminal amino acid residue, which was — leucine-tryptophan. The Sakaguchi reagent was used to confirm arginine as the N-terminal amino acid. The colored p-phenylazophenyl thiohydantions of tryptophan and arginine released from C- and N-terminals respectively were quantitatively estimated and from this molecular weights of buffaloaS₁ casein were calculated and found to be 26,300 and 26,100 respectively.Acknowledgment. We are thankful to Prof. B. K. Bachhawat, Indian Institute of Chemical Biology, for encouragement. We also thank Prof. S. K. Mukherjee, Bose Institute, for amino acid analysis. Part of this work was completed when the authors were at the University of Kalyani, West Bengal.