Reaction of a polypeptide,composed of 12 amino acids,with carboxypeptidase A releases Met (C-terminal amino acid).The polypeptide undergoes partial hydrolysis to give 12 groups of peptides.Use the groups of overlapping amino acids to determine the proper sequence of this polypeptide.Note: Since these lists of peptides are separated by commas,they are not necessarily in the proper sequence. Ser,Lys,Trp-5.Met,Ala,Gly- 9.Lys,Ser
Gly,His,Ala-6.Ser,Lys,Val -10.Glu,His,Val
Glu,Val,Ser-7.Glu,His-11.Trp,Leu,Glu
Leu,Glu,Ser-8.Leu,Lys,Trp-12.Ala,Met

Question

Quizplus · Accepted Answer

- First, we know from the question that the C-terminal amino acid is Met.
- From group 9, we know that Gly comes after Met.
- From group 6, we know that His comes after Gly.
- From group 7, we know that Glu comes after His.
- From group 8, we know that Ser comes after Glu.
- From group 11, we know that Trp comes after Ser.
- From group 12, we know that Leu comes after Trp.
- From group 10, we know that Val comes after Leu.
- From group 5, we know that Lys comes after Val.
- From group 1, we know that Ser comes before Lys.
- From group 2, we know that Trp comes before Ser.
- From group 3, we know that Lys comes after Trp.
- From group 4, we know that Ala comes after Lys.

Putting all of this information together gives us the sequence: Met-Ala-Gly-His-Glu-Val-Ser-Lys-Trp-Leu-Glu-Ser, which matches choice C.

Reaction of a Polypeptide,composed of 12 Amino Acids,with Carboxypeptidase a Releases