4 pyridoxolactonase

In enzymology, a 4-pyridoxolactonase (EC 3.1.1.27) is an enzyme that catalyzes the chemical reaction

Thus, the two substrates of this enzyme are 4-pyridoxolactone and H₂O, whereas its product is 4-pyridoxate.

This enzyme belongs to the family of hydrolases, specifically those acting on carboxylic ester bonds. The systematic name of this enzyme class is 4-pyridoxolactone lactonohydrolase. This enzyme participates in vitamin B₆ metabolism.