ABSTRACT

Chitin is an unbranched polysaccharide comprising of multiple repetitive units of β(1,4)-linked N-acetyl-d-glucosamine. It is the third most abundant biopolymer on earth after cellulose, and is found mainly in insect exoskeletons, crustacean shells, and fungal cell walls. The enzymatic breakdown of chitin is mediated by chitinases, which hydrolyze the β-1,4-N-acetyl-d-glucosamine bonds. Chitinases are needed for ecdysis in growing insects and crustaceans [1], but also in fungi [2]. Chitinases are also known to have digestive functions and can reach very high concentrations in the pancreatic secretions of sh [3]. An acidic chitinase expressed in parts of the stomach with a low pH optimum has been more recently described in mammals [4,5]. Plant chitinases are prominent allergens and are thought to play a role in antifungal immunity [6].