Distance measurements on a dual-labeled TOAC AChR M2δ peptide in mechanically aligned DMPC bilayers via dipolar broadening CW-EPR spectroscopy.

ABSTRACT: A membrane alignment technique has been used to measure the distance between two TOAC nitroxide spin labels on the membrane-spanning M2δ, peptide of the nicotinic acetylcholine receptor (AChR), via CW-EPR spectroscopy. The TOAC-labeled M2δ peptides were mechanically aligned using DMPC lipids on a planar quartz support, and CW-EPR spectra were recorded at specific orientations. Global analysis in combination with rigorous spectral simulation was used to simultaneously analyze data from two different sample orientations for both single- and double-labeled peptides. We measured an internitroxide distance of 14.6 Å from a dual TOAC-labeled AChR M2δ peptide at positions 7 and 13 that closely matches with the 14.5 Å distance obtained from a model of the labeled AChR M2δ peptide. In addition, t

SUBMITTER: Ghimire H 

PROVIDER: S-EPMC3322368 | biostudies-literature | 2012 Mar

REPOSITORIES: biostudies-literature