In enzymology, an inosinate nucleosidase () is an enzyme that catalyzes the chemical reaction 5'-inosinate + H2O D-ribose 5-phosphate + hypoxanthine Thus, the two substrates of this enzyme are 5'-inosinate and H2O, whereas its two products are D-ribose 5-phosphate and hypoxanthine. This enzyme belongs to the family of hydrolases, specifically those glycosylases that hydrolyse N-glycosyl compounds. The systematic name of this enzyme class is 5'-inosinate phosphoribohydrolase. This enzyme participates in purine metabolism. References EC 3.2.2 Enzymes of unknown structure