Flavin-binding glucose dehydrogenase variant

The present invention relates to FAD-GDH which comprises an amino-acid sequence represented by SEQ ID NO: 1 or 3, an amino-acid sequence which is at least 70% identical to the amino-acid sequence represented by SEQ ID NO: 1 or 3, or an amino-acid sequence having the deletion, substitution, or addition of one to several amino acids in such amino-acid sequence (the amino-acid sequence represented by SEQ ID NO: 1, or the amino-acid sequence which is at least 70% identical to the amino-acid sequence represented by SEQ ID NO: 1). The present invention is characterized by having an amino-acid substitution at positions corresponding to the following amino-acids: amino acid at position 175 in the amino-acid sequence depicted in SEQ ID NO: 1; amino acid at position 214 in the amino acid sequence depicted in SEQ ID NO: 1; amino acid at position 192 in the amino-acid sequence depicted in SEQ ID NO: 1; amino acid at position 212 in the amino-acid sequence depicted in SEQ ID NO: 1; amino acid at position 218 in the amino-acid sequence depicted in SEQ ID NO: 1; and/or amino acid at position 226 in the amino-acid sequence depicted in SEQ ID NO: 1. The present invention is also characterized in that the amino-acid sequence has improved thermal stability compared to that prior to the substitution. However, the present invention excludes FAD-GDH comprising an amino-acid sequence represented by SEQ ID NO: 28, 30 or 32.