title: A method for dynamic nuclear polarization enhancement of membrane proteins.
abstract: Dynamic nuclear polarization (DNP) magic-angle spinning (MAS) solid-state NMR (ssNMR) spectroscopy has the potential to enhance NMR signals by orders of magnitude and to enable NMR characterization of proteins which are inherently dilute, such as membrane proteins. In this work spin-labeled lipid molecules (SL-lipids), when used as polarizing agents, lead to large and relatively homogeneous DNP enhancements throughout the lipid bilayer and to an embedded lung surfactant mimetic peptide, KL4 . Specifically, DNP MAS ssNMR experiments at 600 MHz/395 GHz on KL4 reconstituted in liposomes containing SL-lipids reveal DNP enhancement values over two times larger for KL4 compared to liposome suspensions containing the biradical TOTAPOL. These findings suggest an alternative sample preparation strategy for DNP MAS ssNMR studies of lipid membranes and integral membrane proteins.
authors.affiliation: Department of Chemistry, University of Florida, 214 Leigh Hall Gainesville, FL 32611-7200 (USA).
authors.forename: Adam N
authors.initials: AN
authors.lastname: Smith
authors.forename: Marc A
authors.initials: MA
authors.lastname: Caporini
authors.forename: Gail E
authors.initials: GE
authors.lastname: Fanucci
authors.forename: Joanna R
authors.initials: JR
authors.lastname: Long
mesh_terms: D003497:Cyclic N-Oxides / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D010767:Phosphorylcholine / Q000737:chemistry; D020005:Propanols / Q000737:chemistry; D013113:Spin Labels
chemical_list: C521769:1-(TEMPO-4-oxy)-3-(TEMPO-4-amino)propan-2-ol; D003497:Cyclic N-Oxides; D008055:Lipids; D008081:Liposomes; D008565:Membrane Proteins; D020005:Propanols; D013113:Spin Labels; D010767:Phosphorylcholine
keywords: analytical methods; biomembranes; dynamic nuclear polarization; polarizing agents; solid-state NMR spectroscopy