title: Infrared spectroscopic markers of quinones in proteins from the respiratory chain.
abstract: In bioenergetic systems quinones play a central part in the coupling of electron and proton transfer. The specific function of each quinone binding site is based on the protein-quinone interaction that can be described by means of reaction induced FTIR difference spectroscopy, induced for example by light or electrochemically. The identification of sites in enzymes from the respiratory chain is presented together with the analysis of the accommodation of different types of quinones to the same enzyme and the possibility to monitor the interaction with inhibitors. Reaction induced FTIR difference spectroscopy is shown to give an essential information on the general geometry of quinone binding sites, the conformation of the ring and of the substituents as well as essential structural information on the identity of the amino-acid residues lining this site. This article is part of a Special Issue entitled: Vibrational spectroscopies and bioenergetic systems.
authors.affiliation: Laboratoire de bioélectrochimie et spectroscopie, UMR 7140, Chimie de la matière complexe, Université de Strasbourg, 1, rue Blaise Pascal, 67008 Strasbourg, France. Electronic address: hellwig@unistra.fr.
authors.forename: Petra
authors.initials: P
authors.lastname: Hellwig
mesh_terms: D001665:Binding Sites; D004579:Electron Transport / Q000502:physiology*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry / Q000378:metabolism; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism*; D011809:Quinones / Q000737:chemistry* / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; D011506:Proteins; D011809:Quinones
keywords: Electrochemistry; FTIR spectroscopy; Quinol oxidase; Quinone; bc(1) complex; bd oxidase