Chapter 17, Problem 39P

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

Complete hydrolysis of the peptide yields Arg, 2 Gly, Ile, 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. 1. Gly-Leu-Tyr-Phe-Lys-Ser-Met
2. 2. Gly-Leu-Tyr-Lys-Val-Ile-Arg-Met
3. 3. Leu-Pro-Phe

Treatment with trypsin yields the following four peptides:

1. 1. Gly-Leu-Tyr-Phe-Lys
2. 2. Ser-Met-Gly-Leu-Tyr-Lys
3. 3. Val-Ile-Arg
4. 4. Met-Leu-Pro-Phe