Treatment of a polypeptide with 2-mercaptoethanol yields two polypeptides with the following primary sequences:
Val-Met-Tyr-Ala-Cys-Ser-Phe-Ala-Glu-Ser
Ser-Cys-Phe-Lys-Cys-Trp-Lys-Tyr-Cys-Phe-Arg-Cys-Ser
Treatment of the original intact polypeptide with chymotrypsin yields the following peptides:
a. Ala, Glu, Ser
b. 2 Phe, 2 Cys, Ser
c. Tyr, Val, Met
d. Arg, Ser, Cys
e. Ser, Phe, 2 Cys, Lys, Ala, Trp
f. Tyr, Lys
Determine the positions of the disulfide bridges in the original polypeptide.