[1] Univ Basque Country, Dept Biochem & Mol Biol, Leioa 48940, Spain
[2] Univ Basque Country, CSIC, Biofisika Inst, Leioa 48940, Spain
[3] Case Western Reserve Univ, Dept Pharmacol, Sch Med, Cleveland, OH 44106 USA
[4] Case Western Reserve Univ, Dept Physiol Biophys, Sch Med, Cleveland, OH 44106 USA
[5] Case Western Reserve Univ, Cleveland Ctr Membrane & Struct Biol, Sch Med, Cleveland, OH 44106 USA