title: Magic-angle-spinning solid-state NMR of membrane proteins.
abstract: Solid-state NMR spectroscopy (ssNMR) provides increasing possibilities to examine membrane proteins in different molecular settings, ranging from synthetic bilayers to whole cells. This flexibility often enables ssNMR experiments to be directly correlated with membrane protein function. In this contribution, we discuss experimental aspects of such studies starting with protein expression and labeling, leading to membrane protein isolation or to membrane proteins in a cellular environment. We show that optimized procedures can depend on aspects such as the achieved levels of expression, the stability of the protein during purification or proper refolding. Dealing with native membrane samples, such as isolated cellular membranes, can alleviate or entirely remove such biochemical challenges. Subsequently, we outline ssNMR experiments that involve the use of magic-angle-spinning and can be used to study membrane protein structure and their functional aspects. We pay specific attention to spectroscopic issues such as sensitivity and spectral resolution. The latter aspect can be controlled using a combination of tailored preparation procedures with solid-state NMR experiments that simplify the spectral analysis using specific filtering and correlation methods. Such approaches have already provided access to obtain structural views of membrane proteins and study their function in lipid bilayers. Ongoing developments in sample preparation and NMR methodology, in particular in using hyperpolarization or proton-detection schemes, offer additional opportunities to study membrane proteins close to their cellular function. These considerations suggest a further increase in the potential of using solid-state NMR in the context of prokaryotic or eukaryotic membrane protein systems in the near future.
authors.affiliation: NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
authors.forename: Lindsay A
authors.initials: LA
authors.lastname: Baker
authors.affiliation: NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
authors.forename: Gert E
authors.initials: GE
authors.lastname: Folkers
authors.affiliation: NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
authors.forename: Tessa
authors.initials: T
authors.lastname: Sinnige
authors.affiliation: NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
authors.forename: Klaartje
authors.initials: K
authors.lastname: Houben
authors.affiliation: NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Kaplan
authors.affiliation: NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
authors.forename: Elwin A W
authors.initials: EA
authors.lastname: van der Cruijsen
authors.affiliation: NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, The Netherlands. Electronic address: m.baldus@uu.nl.
authors.forename: Marc
authors.initials: M
authors.lastname: Baldus
mesh_terms: D000818:Animals; D003902:Detergents / Q000737:chemistry; D006801:Humans; D008051:Lipid Bilayers / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry* / Q000302:isolation & purification; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D017433:Protein Structure, Secondary; D011510:Proteolipids / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification; D012995:Solubility
chemical_list: D003902:Detergents; D008051:Lipid Bilayers; D008565:Membrane Proteins; D011510:Proteolipids; D011994:Recombinant Proteins; C020485:proteoliposomes
keywords: Cellular envelope; Dynamic nuclear polarization; Ion channel; Membrane proteins; Proteoliposome; Solid-state NMR; β-Barrel protein