嘌呤核苷磷酸化酶英语：Purine nucleoside phosphorylase，简写为PNPase)是参与嘌呤代谢的一种酶。嘌呤核苷磷酸化酶可以代谢腺苷到腺嘌呤，肌苷到次黄嘌呤，鸟苷到鸟嘌呤，并在这些反应中产生核糖-5-磷酸。

需要注意的是，PNPase这一简称还被用于另一个不相关的酶，多核苷酸磷酸化酶（Polynucleotide Phosphorylase）。

Purine nucleoside phosphorylase also known as PNPase and inosine phosphorylase is an enzyme that in humans is encoded by the NP gene.

In enzymology, a purine-nucleoside phosphorylase (EC2.4.2.1) is an enzyme that catalyzes the chemical reaction

Thus, the two substrates of this enzyme are purine nucleoside and phosphate, whereas its two products are purine and alpha-D-ribose 1-phosphate.