FEBS Letters | |
EPR spectroscopy of 5‐DOXYL‐stearic acid bound to the mitochondrial uncoupling protein reveals its competitive displacement by alkylsulfonates in the channel and allosteric displacement by ATP | |
Trommer, Wolfgang E.2  Bauer, Michael2  Ježek, Petr1  | |
[1] Institute of Physiology, Department of Membrane Transport Biophysics, Academy of Sciences of the Czech Republic Vídeňska 1083, CZ 14220 Prague, Czech Republic;Fachbereich Chemie, Universität Kaiserslautern, Erwin-Schrödinger Strasse, D-67663 Kaiserslautern, Germany | |
关键词: Uncoupling protein; Anion channel; Alkylsulfonate; Fatty acid binding site; 5-DOXYL-stearic acid; BAT; brown adipose tissue; NEM; N-ethylmaleimide; 5-SASL; 5-DOXYL-stearic acid; where DOXYL is 4; 4-dimethyl-3-oxazolinyloxy-residue; N 6-SL-ATP; N 6-(2; 2; 6; 6-tetramethyl-piperidin4-yl-1-oxyl)-ATP; TEA; tetraethylammonium; TES; N-Tris(hydroxymethyl)methyl)-2-aminoethane-sulfonic acid; UcP; uncoupling protein; | |
DOI : 10.1016/0014-5793(95)00201-J | |
学科分类:生物化学/生物物理 | |
来源: John Wiley & Sons Ltd. | |
【 摘 要 】
Competition of fatty acids (FA) and alkylsulfonates with 5-DOXYL-stearic acid (5-SASL) binding to isolated mitochondrial uncoupling protein (UcP) is demonstrated using EPR spectroscopy. A distinct peak of the bound 5-SASL (h+1I) decreased with increasing concentration of competitors. Since alkylsulfonates are UcP substrates, it suggests that the FA binding site is located in the anion channel. Moreover, with increasing ATP the h+1I peak decreased and was smoothed with the ‘micellar’ peak into a single wider peak. A pH of 8.5 reversed this effect. It could reflect an allosteric release of 5-SASL from the ATP binding site which mimics the ATP gating mechanism.
【 授权许可】
Unknown
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