A recombinant protein, including: (a) alpha subunit of an FAD-GDH; and (b) a minimal cytochrome c peptide is provided. Additionally, an electrode coupled to a recombinant protein, the recombinant protein made of: (a) a cofactor of a redox enzyme; (b) a redox enzyme; (c) a linker moiety configured to link any one of: the cofactor or the enzyme to an electron transfer (ET) domain; and (d) an ET domain, is also provided. Methods for: (a) transferring an electron to an electrode, by coupling the recombinant protein an electrode; and (b) quantifying the amount of an analyte e.g., glucose are also provided.

Provided is a means for promoting electron transfer between nanocarbon and other substances. An electron transfer accelerator for nanocarbon comprising a compound having an aromatic ring skeleton.

The invention relates to a biocell (1) with a biofuel reservoir intended to be brought into contact with a liquid medium and with a fluid medium comprising an oxidant. Said biocell comprises a first electrochemical cell having: an anode (5) comprising a first enzyme capable of catalyzing the oxidation of the biofuel;—a cathode (7) comprising a second enzyme capable of catalyzing the reduction of the oxidant; and—a separating and porous membrane (3), electrically insulating, and permeable to said liquid medium, placed between the anode (5) and the cathode (7). Said biocell (1) being characterized in that it comprises a means for storing the biofuel (3) and for providing the liquid medium to the anode (5), said means comprising a hydrophilic porous material in contact with said anode (5)) and having a basis weight of 500 to 900 g/m2,

The present invention relates to FAD-GDH consisting of the amino acid sequence of SEQ ID NO: 1 or 3, an amino acid sequence having an identity of 70% or more with the amino acid sequence of SEQ ID NO: 1 or 3, or an amino acid sequence having a deletion, substitution or addition of one or several amino acids in the amino acid sequence (the amino acid sequence of SEQ ID NO: 1 or the amino acid sequence having an identity of 70% or more with the amino acid sequence of SEQ ID NO: 1); having an amino acid substitution at the position(s) corresponding to the following amino acid(s): the amino acid at the 175th position in the amino acid sequence of SEQ ID NO: 1, the amino acid at the 214th position in the amino acid sequence of SEQ ID NO: 1, the amino acid at the 192nd position in the amino acid sequence of SEQ ID NO: 1, the amino acid at the 212th position in the amino acid sequence of SEQ ID NO: 1, the amino acid at the 218th position in the amino acid sequence of SEQ ID NO: 1, and/or the amino acid at the 226th position in the amino acid sequence of SEQ ID NO: 1; and having an improved thermal stability compared to that before the substitution, provided that an FAD-GDH consisting of the amino acid sequence of SEQ ID NO: 28, 30 or 32 is excluded.

The present invention addresses the problem of providing: a glucose dehydrogenase; a polynucleotide encoding the enzyme; a method for producing the enzyme; a method for measuring glucose using the enzyme; a measurement reagent composition; and a biosensor. The present invention pertains to a protein that has any of amino acid sequences (a), (b) and (c) and has a glucose dehydrogenase activity, etc.: (a) an amino acid sequence represented by SEQ ID NO: 3, 6, 15 or 16; (b) an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 3, 6, 15 or 16 by deleting, substituting or adding 1-3 amino acids; and (c) an amino acid sequence having 90% or more identity to the amino acid sequence represented by SEQ ID NO: 3 or 15 or 85% or more identity to the amino acid sequence represented by SEQ ID NO: 6 or 16.

There is provided a biosensor for measuring a measuring target substance in a sample comprising an insulating substrate, an electrode pair provided on the insulating substrate, and a reagent that includes an oxidoreductase and an electron transfer substance and is provided at least on a working electrode of the electrode pair, wherein the working electrode is composed of one or more kinds of nickel alloys selected from the group consisting of a nickel-ruthenium alloy, a nickel-tungsten alloy, and a nickel-vanadium alloy.

A polypeptide comprising a residue substituted by a non-canonical amino acid (ncAA) is provided. Methods for: (a) transferring an electron to an electrode, by coupling the polypeptide to an electrode; and (b) quantifying the amount of an analyte e.g., glucose are also provided.

Provided is GDH with increased applicability to glucose sensors. A composition contains FADGDH, wherein when 0.1 mL of the composition is added to 2.9 mL of a solution containing 10 mM of trehalose and 1 mmol/L of potassium ferricyanide to give a glucose dehydrogenase activity of 500 U/mL and incubated at 37 C., the decrease in absorbance at 405 nm resulting from reduction of the potassium ferricyanide is less than 20 mAbs per minute.

The present invention provides members that produce on a large scale a coenzyme-linked glucose dehydrogenase which has excellent substrate-recognizing ability toward glucose while providing low action on maltose. The present invention relates to a polynucleotide encoding a soluble coenzyme-linked glucose dehydrogenase that catalyzes the oxidation of glucose in the presence of an electron acceptor and has an activity toward maltose of 5% or lower; a polypeptide encoded by the nucleotide sequence of the polynucleotide; a recombinant vector carrying the polynucleotide; a transformed cell produced using the recombinant vector; a method for producing a polypeptide comprising culturing the transformed cell and collecting from the cultivated products a polypeptide that links to FAD to exert the glucose dehydration activity; a method for determination of glucose using the polypeptide; a reagent composition for determination of glucose; and a biosensor.

The purpose of the present invention is to provide a fungus-derived FADGDH that has a direct electron transfer ability. Provided is a fusion protein comprising a fungus-derived FADGDH or a mutant thereof and a cytochrome molecule connected to the N-terminus of the FADGDH or variant thereof.