Patent ID: 7476525

Claim:
An isolated modified pyrroloquinoline quinone dependent glucose dehydrogenase (PQQGDH), consisting of the amino acid sequence of SEQ ID NO: 2 except that (a) the glutamine at position 168 is substituted with an amino acid other than glutamine, (b) optionally one or more amino acids at positions selected from the group consisting of positions 67, 68, 69, 76, 89, 167, 169, 341, 342, 343, 351, 49, 174, 188, 189, 207, 215, 245, 300, 349, 129, 130 and 131 of the amino acid sequence of SEQ ID NO: 2 are substituted with a different amino acid than the amino acid in the corresponding position in the amino acid sequence of SEQ ID NO: 2, and (c) optionally an amino acid is inserted between positions 428 and 429 of the amino acid sequence of SEQ ID NO: 2, wherein the modified PQQGDH has less dehydrogenase activity on maltose than wild-type PQQGDH.