Biochemistry, Microbiology & Molecular Biology

Analysis of a hexapeptide using enzymatic cleavage reveals the following result:  Amino acid composition of the peptide is: 2R, A,V, S, Y  Trypsin digestion yields two fragments and the compositions are: (R, A, V) and (R, S, Y)  Chymotrypsin digestion yields two fragments and the compositions are: (A, R, V, Y) and (R, S)  Digestion with carboxypeptidase A yields no cleavage product. Given: Trypsin cleaves at carboxyl side of R. Chymotrypsin cleaves at carboxyl side of Y. Carboxypeptidase A cleaves at amino side of the C-terminal amino acid (except R and K) of the peptide. The correct amino acid sequence of the peptide is: (A) RSYRVA (B) AVRYSR (C) SRYVAR (D) SVRRYA