Phosphopentomutase

Phosphopentomutase (PGM2) is a metabolic enzyme that catalyzes the conversion of nucleoside breakdown products ribose-1-phosphate and deoxyribose-1-phosphate to their corresponding 5-phosphopentoses (UniProt: Q96G03). It also reversibly isomerizes glucose 1-phosphate to glucose 6-phosphate, though with lower catalytic efficiency, proceeding through an intermediate alpha-D-glucose 1,6-bisphosphate (UniProt: Q96G03). The enzyme plays a role in nucleotide and carbohydrate metabolism.

PGM2 is expressed in human tissues with metabolic roles in nucleotide salvage and glycolysis-related pathways. No disease associations are documented in UniProt curated records.

In Alzheimer's disease, PGM2 shows increased abundance in post-mortem AD brain tissue relative to age-matched controls (Chaparral AD proteomics). The protein was detected across 2 of 4 subcellular fractions in TMT-labeled tandem mass spectrometry analysis, with a mean log2 fold-change of +0.48, indicating upregulation in the disease state. This elevation may reflect altered glucose metabolism or nucleotide salvage pathways in AD brain.