Patent ID: 7550274

Claim:
An isolated mutant water-soluble glucose dehydrogenase having pyrroloquinoline quinone as a coenzyme, wherein said mutant is a mutant of a glucose dehydrogenase comprising the amino acid sequence of SEQ ID NO: 1, and wherein said mutant consists of an amino acid substitution selected from the group consisting of: (1) glutamine at position 168 of SEQ ID NO:1 is substituted with glycine, glutamic acid, leucine, phenylalanine, serine or aspartic acid, optionally combined with (a) a substitution wherein aspartate at position 143 of SEQ ID NO: 1 is substituted with glutamic acid or (b) a substitution wherein asparagine at position 428 of SEQ ID NO:1 is substituted with threonine; (2) leucine at position 169 of SEQ ID NO:1 substituted with alanine, glycine, methionine, tryptophan or lysine, optionally combined with (a) a substitution wherein aspartate at position 143 of SEQ ID NO:1 is substituted with glutamic acid or (b) a substitution wherein asparagine at position 428 of SEQ ID NO:1 is substituted with threonine ; and (3) aspartate at position 143 of SEQ ID NO:1 is substituted with glutamic acid and asparagine at position 428 of SEQ ID NO: 1 is substituted with threonine.