earticle

영어

Lytic polysaccharide monooxygenases (LPMOs) are copper ion containing enzymes to cleave crystalline cellulose or chitin through an oxidative mechanism. Despite the importance of LPMOs for biomass decomposition, basic biochemical methods for characterizing LPMOs, such as activity assays are not well developed. Generally, LPMO activity has been determined by HPLC analysis of the product by simultaneous action of a LPMO and one of a cellulase and a chitinase depending on LPMO’s substrate specificity. Recently a spectrophotometric method has been developed using the side reaction of LPMOs to produce H2O2 in the absence of polysaccharide substrates. However, both assay methods do not give the information about polysaccharide lysis by only LPMOs. In this study, we developed an assay method for LPMOs based on the consumption of ascorbic acid that was used as an external electron donor for LPMOs. The assay method allowed determining the concentration-dependent activity of a chitin active LPMO from Bacillus atrophaeus 1942. This assay method would be a useful tool for detail characterization of LPMOs.