Biochemistry 6th Edition by Reginald Garrett,Charles Grisham

Exercise 7

Solving the sequence of an oligopeptide from sequence analysis data
An octapeptide consisting of 2 Gly, 1 Lys, 1 Met, 1 Pro, 1 Arg, 1 Trp, and 1 Tyr was subjected to sequence studies. The following was found:
a. Edman degradation yielded

b. Upon treatment with carboxypeptidases A, B, and Y, only carboxypeptidase Y had any effect.
c. Trypsin treatment gave two tripeptides and a dipeptide.
d. Chymotrypsin treatment gave two tripeptides and a dipeptide. Acid hydrolysis of the dipeptide yielded only Gly.
e. Cyanogen bromide treatment yielded two tetrapeptides.
f. Clostripain treatment gave a pentapeptide and a tripeptide.
What is the amino acid sequence of this octapeptide?