Macroscopic Orientation of Natural and Model Membranes for Structural Studies (original) (raw)

1997, Analytical Biochemistry

recent years solid-state NMR spectroscopy (3, 4) on One approach for obtaining high-resolution strucmacroscopically oriented lipid bilayers has rapidly tural and functional information for biomembranes emerged as an alternative approach to elucidate strucand their proteins is by static solid-state NMR of oritural and functional features of membrane-bound pepented systems. Here, a general procedure to align fully tides and proteins. In such aligned systems, lipids and functional biological membranes containing large proteins are arranged uniaxially around the memmembrane proteins (M r ú30,000) is described. The brane, allowing normal orientation of the molecule method, based on the isopotential spin-dry ultracenbackbone relative to the substratum. In combination trifugation technique, relies on the centrifugation of with isotopic labeling (e.g., 2 H, 13 C, 15 N) this NMR apmembrane fragments onto a support with simultaneproach has successfully been used to determine the ous, or subsequent, partial evaporation of the solvent complete secondary structure of the M2 channel pepwhich aids alignment. The quality of orientation, as tide and fd coat protein (3), while the orientation of shown by the mosaic spread of the samples, was monithe antibiotic peptide magainin has been resolved in tored by static solid-state 31 P NMR for the phospholipbilayers (5). The complete secondary structure of gramids and by 2 H NMR for a deuterated retinal in bovine icidin and its dynamic properties in membranes have rhodopsin. The generality of this method is demonalso been obtained using 2 H and 15 N NMR (6-9). In strated with three different membranes containing boaddition, the complete structure and orientation of deuvine rhodopsin in reconstituted bilayers, natural terated retinal in bacteriorhodopsin at different states membranes with the red cell anion exchange transport protein in erythrocytes, band 3, and the nicotinic ace-of its photocycle has been resolved (10). The average tylcholine receptor.