title: Mediated spectroelectrochemical titration of proteins for redox potential measurements by a separator-less one-compartment bulk electrolysis method.
abstract: One-compartment bulk electrolysis and simultaneous spectroscopic measurements are realized in a conventional spectroscopic cuvette without separator by using a mesh-type working electrode with extremely large surface area and a wire-type counter electrode with very small surface area. Spectrophotometric monitoring revealed complete electrolysis in a first-order kinetics. This technique was applied to mediated titration of cytochrome c and bilirubin oxidase for determining their redox potentials. Kinetics for the solution redox reaction between protein and mediator is described. The subtraction of spectral background due to mediator adsorption is very easy because of high reproducibility. The experiments can be done under completely anaerobic conditions. Low-absorbance protein samples (of low concentrations or small absorption coefficients) and hydrophobic proteins (such as membrane-bound proteins) are acceptable for measurements.
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto 606-8502, Japan.
authors.forename: Seiya
authors.initials: S
authors.lastname: Tsujimura
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kuriyama
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Fujieda
authors.forename: Kenji
authors.initials: K
authors.lastname: Kano
authors.forename: Tokuji
authors.initials: T
authors.lastname: Ikeda
mesh_terms: D045304:Cytochromes c / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D004572:Electrolysis / Q000379:methods*; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D010084:Oxidation-Reduction; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D011506:Proteins / Q000032:analysis* / Q000737:chemistry*; D017186:Titrimetry
chemical_list: D011506:Proteins; D045304:Cytochromes c; D044925:Oxidoreductases Acting on CH-CH Group Donors; C042401:bilirubin oxidase