Gelatinase is a proteolytic enzyme that allows a living organism to hydrolyse gelatin[1] into its sub-compounds (polypeptides, peptides, and amino acids) that can cross the cell membrane and be used by the organism. It is not a pepsin.

Forms of gelatinases are expressed in several bacteria including Pseudomonas aeruginosa and Serratia marcescens.

In humans, the gelatinases are matrix metalloproteinases MMP2 and MMP9.

Gelatinase is secreted by the stomach.