title: Glucose enzyme electrode using cytochrome b(562) as an electron mediator.
abstract: We demonstrate the construction of glucose sensors employing pyrroloquinoline quinone (PQQ) glucose dehydrogenase (PQQGDH) from Acinetobacter calcoaceticus and glucose oxidase (GOD) from Aspergillus nigar coupled with Escherichia coli soluble cytochrome b(562) (cyt b(562)) as electron acceptor. PQQGDH and GOD do not show direct electrochemical recycling of the prosthetic group at the electrode surface leading to a corresponding current signal. We constructed PQQGDH and GOD electrodes co-immobilized with 100-fold molar excess of cyt b(562) and investigated the electrochemical properties without synthetic electron mediators. PQQGDH/cyt b(562) and GOD/cyt b(562) electrodes both responded well to glucose whereas no current increase was observed from the electrode immobilizing enzyme alone. The detection limits for the PQQGDH/cyt b(562) and GOD/cyt b(562) electrodes were 0.1 and 0.8 mM, respectively, and their linearity extended to over 2 and 9 mM, respectively. These results demonstrate that a sensor system can be constructed without a synthetic electron mediator by using a natural electron acceptor. Furthermore, we have demonstrated the potential application of cyt b(562) in direct electron transfer type sensor systems with oxidoreductases whose quaternary structure do not contain any electron transfer subunit.
authors.affiliation: Department of Biotechnology, Faculty of Technology, Tokyo University of Agriculture and Technology, 2-24-16 Nakamachi, Koganei, 184-8588, Tokyo, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Okuda
authors.forename: Junko
authors.initials: J
authors.lastname: Wakai
authors.forename: Noriko
authors.initials: N
authors.lastname: Yuhashi
authors.forename: Koji
authors.initials: K
authors.lastname: Sode
mesh_terms: D000150:Acinetobacter / Q000201:enzymology; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D003067:Coenzymes; D003573:Cytochrome b Group / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004579:Electron Transport; D004800:Enzymes, Immobilized / Q000737:chemistry; D004926:Escherichia coli / Q000201:enzymology; D029968:Escherichia coli Proteins / Q000737:chemistry*; D005947:Glucose / Q000032:analysis* / Q000737:chemistry; D042843:Glucose 1-Dehydrogenase / Q000737:chemistry*; D005949:Glucose Oxidase / Q000737:chemistry*; D009097:Multienzyme Complexes / Q000737:chemistry; D045542:PQQ Cofactor / Q000737:chemistry*
chemical_list: D003067:Coenzymes; D003573:Cytochrome b Group; D004800:Enzymes, Immobilized; D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; D045542:PQQ Cofactor; C017850:cytochrome b562, E coli; D042843:Glucose 1-Dehydrogenase; D005949:Glucose Oxidase; D005947:Glucose