title: Electro-catalysis by immobilised human flavin-containing monooxygenase isoform 3 (hFMO3).
abstract: Human flavin-containing monooxygenases are the second most important class of drug-metabolizing enzymes after cytochromes P450. Here we report a simple but functional and stable enzyme-electrode system based on a glassy carbon (GC) electrode with human flavin-containing monooxygenase isoform 3 (hFMO3) entrapped in a gel cross-linked with bovine serum albumin (BSA) by glutaraldehyde. The enzymatic electrochemical responsiveness is characterised by using well-known substrates: trimethylamine (TMA), ammonia (NH(3)), triethylamine (TEA), and benzydamine (BZD). The apparent Michaelis-Menten constant (K'(M)) and apparent maximum current (I'(max)) are calculated by fitting the current signal to the Michaelis-Menten equation for each substrate. The enzyme-electrode has good characteristics: the calculated sensitivity was 40.9 +/- 0.5 mA mol(-1) L cm(-2) for TMA, 43.3 +/- 0.1 mA mol(-1) L cm(-2) for NH(3), 45.2 +/- 2.2 mA mol(-1) L cm(-2) for TEA, and 39.3 +/- 0.6 mA mol(-1) L cm(-2) for BZD. The stability was constant for 3 days and the inter-electrode reproducibility was 12.5%. This is a novel electrochemical tool that can be used to investigate new potential drugs against the catalytic activity of hFMO3.
authors.affiliation: Department of Human and Animal Biology, University of Torino, via Accademia Albertina, 13, 10123, Torino, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Castrignanò
authors.forename: Sheila J
authors.initials: SJ
authors.lastname: Sadeghi
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Gilardi
mesh_terms: D002384:Catalysis; D004563:Electrochemistry; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D010105:Oxygenases / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D004800:Enzymes, Immobilized; D010105:Oxygenases; C020066:dimethylaniline monooxygenase (N-oxide forming)