I tired doing it( my answer is in the picture), but it said I labeled 2 of them
ID: 79627 • Letter: I
Question
I tired doing it( my answer is in the picture), but it said I labeled 2 of them incorrectly Thanks MasteringChemistry: Chapter 21 HW ecure https://session.masteringchemistry.com/myct/itemView?offset next&assignmentProblemlDa82125820; ng2017bruice eter 21 HW Problem 21.80 Determine the amino acid sequence of a polypeptide from the folowing data: Complete hydrolysis of the peptide yields Ala, Arg, Gly, 2 Lys, Met, Phe, Pro, 2 Ser, Tyr, and Val. Treatment with Edman's reagent releases PTH-Val. Carboxypeptidase A releases Ala. Treatment with cyanogen bromide yields the following two peptides: 1. Ala, 2 Lys, Phe, Pro, Ser, Tyr 2. Arg, Gly, Met, Ser, Val Treatment with trypsin yields the following three peptides: 1. Gly, Lys, Met, Tyr 2. Ala, Lys, Phe, Pro, Ser 3. Arg, Ser, Val Treatment with chymotrypsin yields the following three peptides: 1.2 Lys, Phe, Pro 2. Arg, Gly, Met, Ser, Tyr, Val 3. Ala, Ser Drag the appropriate labels to their respective targets. Lys Val Ser Arg Gly Met Tyr Lys Lys Phe Pro Ser AlaExplanation / Answer
The acid hydrolysis shows that the polypeptide has 12 amino acids. The N-terminal amino acid is Valine (revealed by edmans reagent) while the Cterminal amino acid id Alanine revealed by carboxypeptidase.
Since the Cyanogen bromide cleaves the C-side of the Met, therefore any peptide containing Met must have Met as its C-terminal Amino acid. The peptide 2 is a N-terminal peptide as it containd Valine and Met is the fifthe amino acid as is clear from the cyanogen bromide data. The c-terminal Amino acid is Alanine.
Val, ser, Arg,Gly, Met, Tyr, Lys, Lys, Phe, Ser, Pro, Ala
As trypsin, cleaves on the C-side of the Arginine and Lysine, any peptide conatining Arg and Lysine, must have that amino acis ad the c-terminal amino acid.
The peptide 3 shows that the Arg is the third amino acid and Ser is the second amino acid, and thus its clear Gly is the fourth amino acid, and Met is the Fifth amino acid.
from the chympotrypsin revealed reaction it is clear that it cleaves at the carboxyl side of the amide bond i.e. at the C-side of the amide bond mainly at Tyr, which is the next amino acid after Met. The reaction will also hydrolyse the two lysine molecules as they contain Met ap P1, therefore the mect will be the 2 Lys, and then Phe, Ser Pro and Ala.