Glutaminyl cyclase

Function

Glutaminyl cyclase (QC) catalyzes the conversion of glutaminyl-peptide to 5-oxoprolyl-peptide and ammonia. Thus QC catalyzes the cyclization of an N-terminal glutamyl residue. QC acts on the generation of N-terminal pyroglutamyl groups of peptide hormones and amyloid-related plaque-forming peptides. The latter contributes to Alzheimer disease.

Disease

Relevance

QC is considered as a marker of thyroid tumors.

Structural highlights