earticle

영어

Lytic polysaccharide monooxygenases (LPMOs) are cupper ion containing enzymes to degrade crystalline polysaccharides, such as cellulose or chitin through an oxidative mechanism. To the best of our knowledge, there is no assay method for direct characterization of LPMOs to degrade the substrates without hydrolases used as the coupled enzymes. In this study, a hydrolase-free assay method for LPMOs was developed, which is based on measuring the consumption of ascorbic acid used as an external electron donor for LPMOs. The ascorbate-based assay method yielded a pH profile with pH 8, which was consistent with the analysis of synergestic effect of BatLPMO10 for chitin degradation in the presence of a chitinase. In addition, the assay method let us know that BatLPMO10 was inhibited by sodium ion, and BatLPMO10 and the coupling chitinase cooperatively enhanced their activities for the degradation of chitin. In conclusion, the hydrolase-free assay method for the polysaccharide degradation catalyzed by LPMOs has been developed for the first time, and this assay method would be useful to search LPMOs with the same optimum pH as its coupled hydrolases or vise versa for improvement of the biomass degradation.