GMP synthase [glutamine-hydrolyzing]

GMP synthase [glutamine-hydrolyzing] (GMPS) is a metabolic enzyme that catalyzes the final step of GMP biosynthesis, converting xanthine monophosphate to GMP using glutamine and ATP as substrates (UniProt: P49915). This enzyme participates in nucleotide metabolism, essential for nucleic acid synthesis and cellular energy regulation. The protein is 693 amino acids in length with a mass of approximately 76.7 kDa.

GMPS operates within purine biosynthetic pathways critical for normal cellular function across tissues. No specific disease associations are documented in the UniProt record.

In Alzheimer's Disease, GMPS is significantly downregulated in post-mortem AD brain tissue compared to age-matched controls (mean log2 fold-change: −0.248; Chaparral AD proteomics). This reduction was detected across a single subcellular fraction in a TMT-labeled quantitative proteomics study of four subcellular compartments (P2, P3, S2, S3). The downregulation of nucleotide biosynthetic enzymes like GMPS may reflect metabolic dysfunction or altered energetic demand in AD neuropathology.