▎ 摘　　要

NOVELTY - Polypeptide having lytic polysaccharide monooxygenase (LPMO) activity comprising sequence of SEQ ID NO: 1 (comprising a fully defined sequence of 221 amino acids as given in the specification) or functionally equivalent variant, where the functionally equivalent variant has at least 65% sequence identity to the sequence of SEQ ID NO: 1 throughout the whole length of SEQ ID NO: 1, is new. USE - The polypeptide is useful for: degrading chitin; and producing composite material used as bioink for 3D bioprinting or as a substrate for cell growth. ADVANTAGE - The polypeptide provides polypeptide having improved stability lytic polysaccharide monooxygenase activity, and provides enhanced ability to serve as a stable functionalized biomaterial for cell growth in 2D and 3D cultures. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: nucleic acid encoding polypeptide, a vector comprising the nucleic acid or host cell comprising nucleic acid or vector; degrading a polysaccharide comprising (3(1-4) glyosidic bond comprising contacting sample containing polysaccharide with cooperbound polypeptide having lytic polysaccharide monooxygenase (LPMO) activity under suitable conditions for the oxidative cleavage of (3(1-4) glycosidic bond, where the polypeptide having LPMO activity is the polypeptide; producing crystalline nanochitin comprising contacting sample containing chitin with a copper-bound polypeptide having lytic polysaccharide monooxygenase (LPMO) activity under suitable conditions for the oxidative cleavage of chitin, where the polypeptide having LPMO activity is the polypeptide; composite material comprising (a) crystalline nanochitin, where crystalline nanochitin is obtained by a method comprising contacting a sample comprising chitin with copper-bound polypeptide having lytic polysaccharide monooxygenase activity (LPMO) under suitable conditions for the oxidative cleavage of chitin, and (b) carbon material comprising carbon nanotubes, carbon nanofibers, graphene and/or graphene oxide; and preparation of the composite material comprising (i) preparing suspension comprising crystalline nanochitin and carbon material comprising carbon nanotubes, carbon nanofibers, graphene and/or graphene oxide, (ii) mixing suspension, and (iii) optionally reducing carbon material in the mixture of the previous step.