You want to know the amino acid sequence of a purified polypeptide (1341 D). Your new technician has performed the analyses outlined below. Do you have enough data to determine the amino acid sequence?
(a) Partial acid hydrolysis yields tripeptides with the following amino acid sequences as determined by manual Edman degradation: HSE, EGT, DYS, TSD, FTS, YSK.
(b) Dansyl chloride treatment yields H and K.
(c) Brief carboxypeptidase A treatment yields one K per mole peptide (a carboxypeptidase removes one residue at a time from the C-terminus of a polypeptide).
(d) Chymotrypsin treatment yields two peptides (A and B) with molecular masses of 659 D and 467 D, respectively, and a dipeptide composed of S and K. Peptide A
(1) Dansyl chloride treatment yields H.
(2) Brief carboxypeptidase A treatment yields F and T. Peptide B
(3) Dansyl chloride treatment yields T.
(4) Brief carboxypeptidase A treatment yields Y and D.
(e) Trypsin treatment results in no fragmentation of the polypeptide.