Question

Provide a brief (3-4 sentence) biochemical explanation clearly describing the specific effect of the following mutations on chymotrypsin-catalyzed peptide bond cleavage. I specifically want to know if the reaction would be allowed to go to completion (and why) and if not, what specific steps in the native mechanism would be affected and how. (assume the reaction is occurring in the small intestine at pH 7.0).

A) The catalytic chymotrypsin serine residue is mutated to valine

B) The catalytic chymotrypsin histidine residue is mutated to glutamate.

C) The catalytic chymotrypsin residue serine is mutated to threonine

D) The chymotrypsin glycine residue that assists in stabilizing the oxanion intermediate is mutated to alanine.