Biochemistry 4th Edition by Reginald Garrett, Charles Grisham

Exercise 2

Solving the Sequence of an Oligopeptide From Sequence Analysis Data Amino acid analysis of an oligopeptide 7 residues long gave

The following facts were observed:
a. Trypsin treatment had no apparent effect.
b. The phenylthiohydantoin released by Edman degradation was

c. Brief chymotrypsin treatment yielded several products, including a dipeptide and a tetrapeptide. The amino acid composition of the tetrapeptide was Leu, Lys, and Met.
d. Cyanogen bromide treatment yielded a dipeptide, a tetrapeptide, and free Lys.
What is the amino acid sequence of this heptapeptide