title: Infrared spectroscopic studies on reaction induced conformational changes in the NADH ubiquinone oxidoreductase (complex I).
abstract: Redox-dependent conformational changes are currently discussed to be a crucial part of the reaction mechanism of the respiratory complex I. Specialized difference Fourier transform infrared techniques allow the detection of side-chain movements and minute secondary structure changes. For complex I, (1)H/(2)H exchange kinetics of the amide modes revealed a better accessibility of the backbone in the presence of NADH and quinone. Interestingly, the presence of phospholipids, that is crucial for the catalytic activity of the isolated enzyme complex, changes the overall conformation. When comparing complex I samples from different species, very similar electrochemically induced FTIR difference spectra and very similar rearrangements are reported. Finally, the information obtained with variants and from Zn(2+) inhibited samples for the conformational reorganization of complex I upon electron transfer are discussed in this review. This article is part of a Special Issue entitled Respiratory complex I, edited by Volker Zickermann and Ulrich Brandt.
authors.affiliation: Laboratoire de bioelectrochimie et spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS, Strasbourg, France.
authors.forename: Petra
authors.initials: P
authors.lastname: Hellwig
authors.affiliation: Laboratoire de bioelectrochimie et spectroscopie, UMR 7140, Chimie de la Matière Complexe, Université de Strasbourg-CNRS, Strasbourg, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Kriegel
authors.affiliation: Albert-Ludwigs-Universität Freiburg, Institut für Biochemie, Albertstr. 21, 79104 Freiburg i. Br., Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Friedrich
mesh_terms: D001665:Binding Sites; D002384:Catalysis; D004579:Electron Transport; D042967:Electron Transport Complex I / Q000737:chemistry* / Q000648:ultrastructure*; D004789:Enzyme Activation; D008956:Models, Chemical; D056004:Molecular Dynamics Simulation; D009243:NAD / Q000737:chemistry / Q000648:ultrastructure*; D010084:Oxidation-Reduction; D011485:Protein Binding; D011487:Protein Conformation; D017382:Reactive Oxygen Species / Q000138:chemical synthesis; D013055:Spectrophotometry, Infrared / Q000379:methods*; D013329:Structure-Activity Relationship; D014451:Ubiquinone / Q000737:chemistry* / Q000648:ultrastructure*
chemical_list: D017382:Reactive Oxygen Species; D009243:NAD; D014451:Ubiquinone; D042967:Electron Transport Complex I
keywords: Bioenergetics; Complex I; H/D exchange; Infrared; Spectroelectrochemistry