PNP belongs to the PNP/MTAP phosphorylase family of proteins. This protein catalyzes the reversible phosphorolysis of ribonucleosides and 2'-deoxyribonucleosides with specificity for guanine, hypoxanthine and their analogs. PNP deficiency is a rare autosomal recessive genetic disease associated with a severe defect in T-lymphocyte function and neurologic disorder in children, comprising four percent of combined immunodeficiency cases. Recombinant human PNP protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques. MW: 34.2 kDa (309 aa, 1-289 aa + His Tag). Purity ≥90%