title: Stabilisation of tyrosinase by reversed micelles for bioelectrocatalysis in dry organic media.
abstract: The enzymatic and bioelectrocatalytic activity of tyrosinase from mushrooms was studied in a system of reversed micelles formed by Aerosol OT (AOT) in hexane. The optimal catechol oxidising activity of tyrosinase incorporated in reversed micelles was found at a hydration degree of w(0)=25. The catalytic activity was comparable with tyrosinase activity in aqueous media. When immobilized at an Au electrode, either directly or in reversed micelles, tyrosinase exhibited a similar efficiency of the bioelectrocatalytic reduction of O(2) mediated by catechol; however, a rapid decrease in the activity correlated with the destruction of reversed micelles and/or the removal of tyrosinase from the electrode surface. The system containing tyrosinase in reversed micelles with caoutchouk, spread on the surface of the Au electrode and successively covered with a Nafion membrane layer, was found to result in stable tyrosinase-modified electrodes, which were resistant to inactivation in dry acetonitrile. The proposed technique offers possibilities for further development of highly active and stable surfactant/enzyme-modified electrodes for measurements carried out in organic solvents.
authors.affiliation: Department of Chemical Enzymology, Chemical Faculty, Moscow State University, Russia. shipovskov@yahoo.com
authors.forename: Stepan
authors.initials: S
authors.lastname: Shipovskov
authors.forename: Elena
authors.initials: E
authors.lastname: Ferapontova
authors.forename: Tautgirdas
authors.initials: T
authors.lastname: Ruzgas
authors.forename: Andrey
authors.initials: A
authors.lastname: Levashov
mesh_terms: D000363:Agaricales / Q000201:enzymology*; D002384:Catalysis; D004143:Dioctyl Sulfosuccinic Acid; D004566:Electrodes; D008823:Micelles; D014442:Monophenol Monooxygenase / Q000737:chemistry*; D013501:Surface-Active Agents
chemical_list: D008823:Micelles; D013501:Surface-Active Agents; D004143:Dioctyl Sulfosuccinic Acid; D014442:Monophenol Monooxygenase