Protein glutamine glutaminase

In enzymology, a protein-glutamine glutaminase (EC 3.5.1.44) is an enzyme that catalyzes the chemical reaction

Thus, the two substrates of this enzyme are protein L-glutamine and H₂O, whereas its two products are protein L-glutamate and NH₃.

This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in linear amides. The systematic name of this enzyme class is protein-L-glutamine amidohydrolase. Other names in common use include peptidoglutaminase II, glutaminyl-peptide glutaminase, destabilase, and peptidylglutaminase II.