title: Resting state of respiratory Complex I from Escherichia coli.
abstract: Respiratory Complex I from Escherichia coli may exist in two states, resting (R) and active (A). The conversion from the R- to A-forms occurs spontaneously upon turnover. The fast resting-to-active (R/A) transition of membrane-bound and purified Complex I was studied with the stopped-flow technique by following NADH oxidation either by absorption decay at 340 nm or using the fluorescent pH indicator, trisodium 8-hydroxypyrene-1,3,6-trisulfonate (pyranine). The R/A transition of Complex I from E. coli occurs upon its turnover in a time interval of ~ 1.5 s. Comparisons between the bacterial Complex I R/A transition and the active/deactive transition of mitochondrial Complex I are discussed.
authors.affiliation: Institute of Biotechnology, University of Helsinki, Finland.
authors.forename: Nikolai
authors.initials: N
authors.lastname: Belevich
authors.affiliation: Institute of Biotechnology, University of Helsinki, Finland.
authors.forename: Marina
authors.initials: M
authors.lastname: Verkhovskaya
mesh_terms: D001481:Basal Metabolism / Q000235:genetics; D042967:Electron Transport Complex I / Q000378:metabolism*; D004789:Enzyme Activation; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D014451:Ubiquinone / Q000378:metabolism
chemical_list: D009243:NAD; D014451:Ubiquinone; D042967:Electron Transport Complex I
keywords: NADH:ubiquinone oxidoreductase; resting state; stopped-flow technique