Chitinase B (ChiB)

Chitinase B is a hydrolytic enzyme that catalyzes the breakdown of chitin, a major structural polysaccharide found in the exoskeletons of arthropods and cell walls of fungi. It belongs to the glycoside hydrolase family 18 (GH18). Chitinase B performs random endo-hydrolysis of N-acetyl-beta-D-glucosaminide (1→4)-beta-linkages in chitin and chitodextrins. It plays essential roles in degradation of environmental chitin for nutrient acquisition by bacteria or fungi, and defense against fungal pathogens in plants. In mammals (though not directly for ChiB), true chitinases are involved in immune responses despite mammals lacking endogenous chitin production; they may participate in inflammation regulation and tissue injury responses.

Endo-hydrolysis of chitin polymers