Question

The following reagents are often used in protein chemistry: CNBr, Urea, Mercaptoethanol, Chymotrypsin, Trypsin, Performic acid, 6 N HCl, and Phenyl isothiocyanate. Which one is the best suited for accomplishing each of the following tasks?

a) Determination of the amino acid sequence of a small peptide.

b) Reversible denaturation of a protein devoid of disulfide bonds. Which additional reagent would you need if disulfide bonds were present?

c) Hydrolysis of peptide bonds on the carboxyl side of aromatic residues.

d) Cleavage of peptide bonds on the carboxyl side of methionines.

e) Hydrolysis of peptide bonds on the carboxyl side of lysine and arginine residues.