title: Investigating the thermostability of succinate: quinone oxidoreductase enzymes by direct electrochemistry at SWNTs-modified electrodes and FTIR spectroscopy.
abstract: Succinate: quinone reductases (SQRs) are the enzymes that couple the oxidation of succinate and the reduction of quinones in the respiratory chain of prokaryotes and eukaryotes. Herein, we compare the temperature-dependent activity and structural stability of two SQRs, the first from the mesophilic bacterium Escherichia coli and the second from the thermophilic bacterium Thermus thermophilus, using a combined electrochemical and infrared spectroscopy approach. Direct electron transfer was achieved with full membrane protein complexes at single-walled carbon nanotube (SWNT)-modified electrodes. The possible structural factors that contribute to the temperature-dependent activity of the enzymes and, in particular, to the thermostability of the Thermus thermophilus SQR are discussed.
authors.affiliation: Laboratoire de Bioélectrochimie et Spectroscopie, Chimie de la Matière Complexe (UMR 7140), Université de Strasbourg, 1 Rue Blaise Pascal, 67000 Strasbourg (France).
authors.forename: Frederic
authors.initials: F
authors.lastname: Melin
authors.forename: Mohamed R
authors.initials: MR
authors.lastname: Noor
authors.forename: Elodie
authors.initials: E
authors.lastname: Pardieu
authors.forename: Fouzia
authors.initials: F
authors.lastname: Boulmedais
authors.forename: Florian
authors.initials: F
authors.lastname: Banhart
authors.forename: Gary
authors.initials: G
authors.lastname: Cecchini
authors.forename: Tewfik
authors.initials: T
authors.lastname: Soulimane
authors.forename: Petra
authors.initials: P
authors.lastname: Hellwig
mesh_terms: D002384:Catalysis; D055664:Electrochemical Techniques; D004566:Electrodes; D042963:Electron Transport Complex II / Q000737:chemistry* / Q000378:metabolism; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology; D037742:Nanotubes, Carbon / Q000737:chemistry*; D055550:Protein Stability; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D016963:Thermus thermophilus / Q000201:enzymology
chemical_list: D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D042963:Electron Transport Complex II
keywords: IR spectroscopy; nanotubes; reductases; thermostability; voltammetry