Question

Some enzymes have one or more sulfhydryl (thiol) groups that are important to enzymatic activity but that can react upon standing in solution to form inactive disulfide bonds.
Thiol reagents, such as 1,4-dithiothreitol (DTT), are often added to the solutions of such proteins to protect them from this reaction and to reverse it when it occurs. (The reverse reaction works best at slightly alkaline pH.) Draw the product formed when DTT reacts with a protein disulfide bond to liberate the free thiol groups. Which of the following occurs in this reaction? A. The protein disulfide is oxidized.
B. The protein disulfide is reduced.
C. DTT is reduced.
D. DTT is oxidized.

Answer 1

Answer:

A. Protein disulfide is oxidized.

Explanation:

When thiol reagents are introduced with some protein solutions they react with molecules of disulfide and oxidize the protein. There occurs inter-conversion of thiol molecules into free disulfide molecules. The DTT reduces the disulfide molecules bonds of proteins and it starts to peptide.