title: Direct electron transfer to a metagenome-derived laccase fused to affinity tags near the electroactive copper site.
abstract: We demonstrate the efficient direct electron transfer (DET) from an electrode to an engineered laccase isolated from a metagenome. The enzyme has a unique homotrimeric architecture with a two-domain-type laccase subunit. The recombinant laccase-modified mesoporous carbon electrode exhibits an effective catalytic current for oxygen reduction, which depends on the affinity tags attached near the electroactive Cu site of the enzyme. We also investigated the effect of the affinity tags on the orientation of the enzyme on functional thiol-modified Au electrodes. The results suggest that a poly-histidine tag (His-tag) functions as an anchor to control the orientation of the enzyme to enhance the current density of the DET-type bioelectrocatalysis.
authors.affiliation: Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan. seiya@ims.tsukuba.ac.jp.
authors.forename: Seiya
authors.initials: S
authors.lastname: Tsujimura
authors.forename: Masafumi
authors.initials: M
authors.lastname: Asahi
authors.forename: Maiko
authors.initials: M
authors.lastname: Goda-Tsutsumi
authors.forename: Osamu
authors.initials: O
authors.lastname: Shirai
authors.forename: Kenji
authors.initials: K
authors.lastname: Kano
authors.forename: Kentaro
authors.initials: K
authors.lastname: Miyazaki
mesh_terms: D000345:Affinity Labels; D055162:Biocatalysis; D003300:Copper / Q000737:chemistry*; D055664:Electrochemical Techniques; D004566:Electrodes; D004579:Electron Transport; D004583:Electrons; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D042845:Laccase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics
chemical_list: D000345:Affinity Labels; D004800:Enzymes, Immobilized; D011994:Recombinant Proteins; D003300:Copper; D042845:Laccase; D010100:Oxygen