Question

Over time, the glutamine residues of polypeptides are susceptible to deamidation, a reaction in which the amide group is replaced by a carboxylate group. What amino acid is produced when glutamine is deamidated?

Short answer

Glutamine deamidation forms glutamic acid.

Step-by-step solution

What is Deamidation?

Deamidation is a chemical reaction where the side chain of the amino group of either asparagine or glutamine is removed/ converted, resulting in the formation of a new functional group.

Glutamine Deamidation

The nucleophilic attack on the α-amino group of the side-chain amide of Glutamine results in the formation of the Glutamic acid.

Chemical reaction of glutamine deamidation

Hence, Glutamic acid is formed by Glutamine deamidation.