Flat-coil probe for NMR spectroscopy of oriented membrane samples

摘要: A probe optimized for NMR studies of oriented lipid bilayer samples has been developed and demonstrated to be effective in singleand double-resonance experiments with a variety nuclei. This is characterized by having flat radiofrequency coil wrapped directly around pair square glass plates between which the actual sample sandwiched. The very high efficiency results from favorable filling factor, turn allows additional gains through miniaturization all capacitors, leads, connectors. ratio area circumference, reducing edge effects improving macroscopic orientation lipids. Neither nor protein components membranes are amenable structural analysis multidimensional solution because their slow overall reorientation rates. However, structures immobile peptides proteins can determined at atomic resolution solid-state methods when it possible orient respect magnetic field spectrometer (I4). In cases, spontaneous uniaxial occurs due interactions large external field. Magnetic alignment enabled structure coat filamentous bacteriophage fd spectroscopy ( 1, 2). Some specific mixtures protein-containing membrane fragments have found fields (5, 6). exceptional cannot expected work most interest. commonly used technique aligning involves deposition mixture lipids onto followed application pressure, shear, or centrifugal forces 7-1 I ) . degree achieved small amounts placed relatively surface level hydration subsequently reduced. Typically, number rectangular stacked parallel so that reasonable amount material cylindrical (12-14). preparation stacks containing serious limitations. It laborious difficulties arising lipid-containing being extruded plates, uniform pressure over misalignment themselves. addition, factor worse round coil.