Heparinase I can degrade heparin and heparan sulfate, making it a powerful tool for heparin structural research, clinical diagnosis, and industrial quality control.

Heparinase I selectively cleaves the linkages between glucosamine and O-sulfated iduronic acid in heparin and heparan sulfate (relative activity approximately 3:1), with the main products being disaccharides. This enzyme can also cleave the pentasaccharide binding site of antithrombin III within heparin molecules.