Please help and explain !! (5 pts) Determine the amino acid sequence of a polype

Question

Please help and explain !!
(5 pts) 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. Gly-Leu-Tyr-Phe-Lys-Ser-Met 2. Gly-Leu-Tyr-Lys-Val-lle-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-lle-Arg 4. Met-Leu-Pro-Phe

Explanation / Answer

1) treatment with Edman's reagent release PTH-Glycine. edmans degradation is used for amino acid sequencing of peptide/protein and it removes N terminal amino acid and gave us PTH amino acid product.

so the first amino acid is Glycine.

2) Carboxypeptidase A release C terminal amino acid. so the last amino acid is Phe.

3) Cyanogen Bromide chops after Met residue.

so the sequence will be either 1-2-3 or 2-1-3.

4) trypsin chops after basic amino acid- Arg and Lys unless followed by Proline.

so the sequence of the peptide is

1-2-3-4.

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