Chapter 22, Problem 55P

Determine the amino acid sequence of a polypeptide from the following data:

Complete hydrolysis of the peptide yields Arg, 2 Gly, He, 3 Leu, 2 Lys, 2 Met, 2 Phe, Pro, Ser, 2 Tyr, and Val.

Treatment with Edman’s reagent releases PTH-Gly.

Carboxypeptidase A releases Phe.

Treatment with cyanogen bromide yields the following three peptides:

1. Gly-Leu-Tyr-Phe-Lys-Ser-Met

2. Gly-Leu-Tyr-Lys-Val-He-Arg-Met

3. Leu-Pro-Phe

Treatment with trypsin yields the following four peptides:

1. Gly-Leu-Tyr-Phe-Lys

2. Ser-Met-Gly-Leu-Tyr-Lys

3. Val-He-Arg

4. Met-Leu-Pro-Phe