Determining the Helical Tilt Angle of a Transmembrane Helix in Mechanically Aligned Lipid Bilayers Using EPR Spectroscopy

摘要

The utilization of aligned phospholipid bilayers in both NMR and electron paramagnetic resonance (EPR) spectroscopy has provided a wealth of structural and dynamic information about membrane-associated macromolecules. The orientational dependent behavior of various nitroxide spin labels attached to lipids incorporated into aligned membrane systems has been investigated by several researchers, including our recent investigations with bicelles using EPR spectroscopy. For the first time, a spin label rigidly coupled to a peptide backbone was mechanically aligned in planner-supported lipid bilayers to measure the helical tilt angle of a transmembrane helix with EPR spectroscopy.