Reaction: [(1→4)-N-acetyl-β-D-glucosaminyl]m+n + reduced acceptor + O2 = [(1→4)-N-acetyl-β-D-glucosaminyl]m-1-(1→4)-N-acetyl-2-deoxy-2-amino-D-glucono-1,5-lactone + [(1→4)-N-acetyl-β-D-glucosaminyl]n + acceptor + H2O
Other name(s): LPMO (ambiguous); CBP21; chitin oxidohydrolase
Systematic name: chitin, hydrogen-donor:oxygen oxidoreductase (N-acetyl-β-D-glucosaminyl C1-hydroxylating/C4-dehdrogenating)
Comments: The enzyme cleaves chitin in an oxidative manner, releasing fragments of chitin with an N-acetylamino-D-glucono-1,5-lactone at the reducing end. The initially formed lactone at the reducing end of the shortened chitin chain quickly hydrolyses spontaneously to the aldonic acid. In vitro ascorbate can serve as reducing agent. The enzyme contains copper at the active site.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:
References:
1. Vaaje-Kolstad, G., Westereng, B., Horn, S.J., Liu, Z., Zhai, H., Sorlie, M. and Eijsink, V.G. An oxidative enzyme boosting the enzymatic conversion of recalcitrant polysaccharides. Science 330 (2010) 219-222. [PMID: 20929773]
2. Vaaje-Kolstad, G., Bohle, L.A., Gaseidnes, S., Dalhus, B., Bjoras, M., Mathiesen, G. and Eijsink, V.G. Characterization of the chitinolytic machinery of Enterococcus faecalis V583 and high-resolution structure of its oxidative CBM33 enzyme. J. Mol. Biol. 416 (2012) 239-254. [PMID: 22210154]
3. Gudmundsson, M., Kim, S., Wu, M., Ishida, T., Momeni, M.H., Vaaje-Kolstad, G., Lundberg, D., Royant, A., Stahlberg, J., Eijsink, V.G., Beckham, G.T. and Sandgren, M. Structural and electronic snapshots during the transition from a Cu(II) to Cu(I) metal center of a lytic polysaccharide monooxygenase by X-ray photoreduction. J. Biol. Chem. 289 (2014) 18782-18792. [PMID: 24828494]
4. Zhang, H., Zhao, Y., Cao, H., Mou, G. and Yin, H. Expression and characterization of a lytic polysaccharide monooxygenase from Bacillus thuringiensis. Int. J. Biol. Macromol. 79 (2015) 72-75. [PMID: 25936286]