Insulin is a polypeptide hormone that contains two short polypeptide chains linked by two interstrand disulfide bonds. The most logical order of events to perform in order to sequence this protein would be:
A.The peptides are reduced with mercaptoethanol.
B.The peptides are sequenced using Edman chemistry.
C.The peptides are separated by chromatography techniques.
D.The peptides are alkylated with iodoacetamide.
A) A, D, C, B
B) C, A, D, B
C) C, B, A, D
D) A, B, C, D
E) A, C, D, B

Question

Quizplus · Accepted Answer

First, reduce the disulfide bonds with mercaptoethanol (A), then alkylate with iodoacetamide to prevent reformation of disulfide bonds (D), separate the peptides using chromatography (C), and finally sequence them using Edman chemistry (B).

Insulin Is a Polypeptide Hormone That Contains Two Short Polypeptide