Conformational changes involved in MscL channel gating measured using FRET spectroscopy.
We demonstrate that fluorescence resonance energy transfer spectroscopy is a powerful tool for in situ structural analysis of multimeric membrane proteins by measuring the conformational changes involved in gating the mechanosensitive ion channel of large conductance. Ensemble analysis is used to analyze the intensity of light emitted by AlexaFluor-labeled cysteine mutants reconstituted into artificial liposomes before and after acceptor photobleaching. The diameter of the protein is found to increase by 16 A upon channel activation.
Corry
Ben
B
School of Biomedical, Biomolecular and Chemical Science, The University of Western Australia, Crawley, Australia. ben@theochem.uwa.edu.au
Rigby
Paul
P
Liu
Zhen-Wei
ZW
Martinac
Boris
B
D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000648:ultrastructure*; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D015640:Ion Channel Gating; D007473:Ion Channels / Q000737:chemistry* / Q000648:ultrastructure*; D008081:Liposomes / Q000737:chemistry*; D040542:Mechanotransduction, Cellular; D011487:Protein Conformation
D029968:Escherichia coli Proteins; D007473:Ion Channels; D008081:Liposomes; C086596:MscL protein, E coli