Chitosanases are generally defined as enzymes that attack chitosan but not chitin. First desriptions of enzymes with chitosanase activities were published in 1972 by Ramirez-Leon & Ruiz-Herrera (112) and 1973 by Monaghan et al. (87).The definition of chitosanase (EC 220.127.116.11) by the Enzyme Commission has been amended in 2004. Chitosanase is defined as the enzyme performing endohydrolysis of β-1,4-linkages between D-glucosamine residues in a partly N-acetylated chitosan. Further details can be found on the Website of the International Union of Biochemistry and Molecular Biology.
Oligosacharides obtained from chitosan hydrolysis by chitosanase enzymes can be further digested into monomers by N-acetyl-glucosaminidases and/or by exo-glucosaminidases (9)
(10). An E.C. number has been created in 2008 for exo-β-D-glucosaminidase activity (sometimes called "exo-chitosanase"). Details are available on
the Website of the International Union of Biochemistry and Molecular Biology as well on this website.
Fukamizo (2000)(69) and Shinya et al. (2013) (82) reviewed the molecular mechanism and the substate-binding properties of chitosanases and other enzymes acting on similar substrates (chitinases, lysozymes). Blanchard et al. (2003) (66) published a review on potential applications of enzymatically hydrolyzed chitosan. Hoell et al. (2010) reviewed the structure and function of enzymes acting towards chitin and chitosan, including chitinases, chitosanases and chitin deacetylases. (82)