title: Solid state NMR: The essential technology for helical membrane protein structural characterization.
abstract: NMR spectroscopy of helical membrane proteins has been very challenging on multiple fronts. The expression and purification of these proteins while maintaining functionality has consumed countless graduate student hours. Sample preparations have depended on whether solution or solid-state NMR spectroscopy was to be performed - neither have been easy. In recent years it has become increasingly apparent that membrane mimic environments influence the structural result. Indeed, in these recent years we have rediscovered that Nobel laureate, Christian Anfinsen, did not say that protein structure was exclusively dictated by the amino acid sequence, but rather by the sequence in a given environment (Anfinsen, 1973) [106]. The environment matters, molecular interactions with the membrane environment are significant and many examples of distorted, non-native membrane protein structures have recently been documented in the literature. However, solid-state NMR structures of helical membrane proteins in proteoliposomes and bilayers are proving to be native structures that permit a high resolution characterization of their functional states. Indeed, solid-state NMR is uniquely able to characterize helical membrane protein structures in lipid environments without detergents. Recent progress in expression, purification, reconstitution, sample preparation and in the solid-state NMR spectroscopy of both oriented samples and magic angle spinning samples has demonstrated that helical membrane protein structures can be achieved in a timely fashion. Indeed, this is a spectacular opportunity for the NMR community to have a major impact on biomedical research through the solid-state NMR spectroscopy of these proteins.
authors.affiliation: National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA; Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA; Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA. Electronic address: cross@magnet.fsu.edu.
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Cross
authors.affiliation: National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA; Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
authors.forename: Vindana
authors.initials: V
authors.lastname: Ekanayake
authors.affiliation: National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA; Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA.
authors.forename: Joana
authors.initials: J
authors.lastname: Paulino
authors.affiliation: National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA; Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Wright
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry; D001703:Biophysics; D018360:Crystallography, X-Ray; D005227:Fatty Acids / Q000737:chemistry; D006096:Gramicidin / Q000737:chemistry; D009980:Influenza A virus / Q000737:chemistry; D008051:Lipid Bilayers; D008565:Membrane Proteins / Q000737:chemistry*; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D017433:Protein Structure, Secondary
chemical_list: D000900:Anti-Bacterial Agents; D005227:Fatty Acids; D008051:Lipid Bilayers; D008565:Membrane Proteins; D006096:Gramicidin
keywords: Helical membrane proteins; Magic angle spinning NMR; Membrane influence on structure; Membrane protein environment; Membrane protein structure; Oriented sample NMR; PISEMA; Solid state NMR; Structural validation