Mutant glucose oxidase and use thereof
View Patent ↗By using a mutant glucose oxidase comprising an amino acid sequence in which a residue corresponding to isoleucine at position 489 or arginine at position 335 in the amino acid sequence of SEQ ID NO:1 is substituted with an amino acid residue having a reactive functional group in a side chain, and binding an electron acceptor to the mutant glucose oxidase through the amino acid residue having a reactive functional group, an electron acceptor-modified glucose oxidase is obtained.
1. A mutant glucose oxidase comprising an amino acid sequence in which a residue corresponding to isoleucine at position 489 or arginine at position 335 in the amino acid sequence of SEQ ID NO:1 is substituted with an amino acid residue having a reactive functional group in a side chain, wherein said mutant glucose oxidase has an amino acid sequence with a sequence identity of not less than 90% to the amino acid sequence of SEQ ID NO: 1.
2. The mutant glucose oxidase according to claim 1 , wherein the amino acid residue having a reactive functional group in the side chain is a lysine residue.
3. The mutant glucose oxidase according to claim 1 , wherein said mutant glucose oxidase originates from Aspergillus niger.
4. An electron acceptor-modified glucose oxidase obtained or obtainable by introducing an electron acceptor to the mutant glucose oxidase according to claim 1 , wherein the electron acceptor has been introduced to the glucose oxidase through the amino acid residue having a reactive functional group in the side chain.
5. The electron acceptor-modified glucose oxidase according to claim 4 , wherein the electron acceptor is a phenazinium compound.
6. The electron acceptor-modified glucose oxidase according to claim 5 , wherein the phenazinium compound is represented by the following formula:
wherein R1 represents a hydrocarbyl group, and R2 represents a linker.
7. An enzyme electrode comprising an electrode base material and the electron acceptor-modified glucose oxidase according to claim 4 bound to the base material.
8. A biosensor comprising the enzyme electrode according to claim 7 .
9. The mutant glucose oxidase according to claim 1 , wherein said mutant glucose oxidase has an amino acid sequence with a sequence identity of not less than 95% to the amino acid sequence of SEQ ID NO: 1.
10. The mutant glucose oxidase according to claim 1 , wherein said mutant glucose oxidase has an amino acid sequence with a sequence identity of not less than 98% to the amino acid sequence of SEQ ID NO: 1.
11. The mutant glucose oxidase according to claim 1 , wherein the residue corresponding to isoleucine at position 489 in the amino acid sequence of SEQ ID NO:1 is substituted with the amino acid residue having a reactive functional group in a side chain.
12. The mutant glucose oxidase according to claim 1 , wherein the residue corresponding to arginine at position 335 in the amino acid sequence of SEQ ID NO:1 is substituted with the amino acid residue having a reactive functional group in a side chain.