Why is it that unfolded ribonuclease regains only 1 of its a

Why is it that unfolded ribonuclease regains only 1% of its activity when renatured (refolded) when both reducing agent and denaturing agent are removed, but recovers close to full activity when it is renatured in the presence of reducing agent, which is subsequently removed by dialysis?

Solution

Ribonuclease is mainly composed of total eight disulfide residues with which to from 4 disulfide bonds once the protein is properly folded. In case, when the disulfide bonds are going to be allowed to fold prior to the protein structure in its native structure, incorrect disulfide bridges may form between amino acids result in gaining 1% of its activity. This is due to the removal of reducing agent finally creates oxidizing environment. For example, 2-mercaptoethanol is going to disrupt disulfide bridges in the folded protein, if is removed (by dialysis) incorrect disulfide bonds may form instead of refolding with native conformation finally cause protein leads to mis-filded ribonuclease