Highly Efficient Flavin-Adenine Dinucleotide Glucose Dehydrogenase Fused to a Minimal Cytochrome C Domain

J Am Chem Soc. 2017 Dec 6;139(48):17217-17220. doi: 10.1021/jacs.7b07011. Epub 2017 Sep 21.

Abstract

Flavin-adenine dinucleotide (FAD) dependent glucose dehydrogenase (GDH) is a thermostable, oxygen insensitive redox enzyme used in bioelectrochemical applications. The FAD cofactor of the enzyme is buried within the proteinaceous matrix of the enzyme, which makes it almost unreachable for a direct communication with an electrode. In this study, FAD dependent glucose dehydrogenase was fused to a natural minimal cytochrome domain in its c-terminus to achieve direct electron transfer. We introduce a fusion enzyme that can communicate with an electrode directly, without the use of a mediator molecule. The new fusion enzyme, with its direct electron transfer abilities displays superior activity to that of the native enzyme, with a kcat that is ca. 3 times higher than that of the native enzyme, a kcat/KM that is more than 3 times higher than that of GDH and 5 to 7 times higher catalytic currents with an onset potential of ca. (-) 0.15 V vs Ag/AgCl, affording higher glucose sensing selectivity. Taking these parameters into consideration, the fusion enzyme presented can serve as a good candidate for blood glucose monitoring and for other glucose based bioelectrochemical systems.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biocatalysis
  • Blood Glucose / analysis
  • Burkholderia cepacia / enzymology
  • Coenzymes / chemistry
  • Coenzymes / metabolism
  • Cytochromes c / chemistry*
  • Electrodes
  • Electron Transport
  • Flavin-Adenine Dinucleotide / chemistry
  • Flavin-Adenine Dinucleotide / metabolism*
  • Glucose / metabolism
  • Glucose 1-Dehydrogenase / chemistry
  • Glucose 1-Dehydrogenase / metabolism*
  • Protein Domains

Substances

  • Blood Glucose
  • Coenzymes
  • Flavin-Adenine Dinucleotide
  • Cytochromes c
  • Glucose 1-Dehydrogenase
  • Glucose