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Colbasevici A, Voskoboynikova N, Orekhov PS, Bozdaganyan ME, Karlova MG, Sokolova OS, Klare JP, Mulkidjanian AY, Shaitan KV, Steinhoff HJ. Lipid dynamics in nanoparticles formed by maleic acid-containing copolymers: EPR spectroscopy and molecular dynamics simulations. Biochim Biophys Acta Biomembr 2020; 1862:183207. [PMID: 31987867 DOI: 10.1016/j.bbamem.2020.183207] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/22/2020] [Accepted: 01/23/2020] [Indexed: 12/11/2022]
Abstract
Amphiphilic maleic acid-containing copolymers account for a recent methodical breakthrough in the study of membrane proteins. Their application enables a detergent-free extraction of membrane proteins from lipid bilayers, yielding stable water-soluble, discoidal lipid bilayer particles with incorporated proteins, which are wrapped with copolymers. Although many studies confirm the potential of this approach for membrane protein research, the interactions between the maleic acid-containing copolymers and extracted lipids, as well as possible effects of the copolymers on lipid-embedded proteins deserve further scrutinization. Here, we combine electron paramagnetic resonance spectroscopy and coarse-grain molecular dynamics simulations to compare the distribution and dynamics of lipids in lipid particles of phospholipid bilayers encased either by an aliphatic diisobutylene/maleic acid copolymer (DIBMALPs) or by an aromatic styrene/maleic acid copolymer (SMALPs). Nitroxides located at the 5th, 12th or 16th carbon atom positions in phosphatidylcholine-based spin labels experience restrictions of their reorientational motion depending on the type of encasing copolymer. The dynamics of the lipids was less constrained in DIBMALPs than in SMALPs with the affinity of spin labeled lipids to the polymeric rim being more pronounced in SMALPs.
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Affiliation(s)
| | | | - Philipp S Orekhov
- Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia; Sechenov University, Moscow 119146, Russia; Department of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Marine E Bozdaganyan
- Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia; Department of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow 119991, Russia
| | - Maria G Karlova
- Department of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Olga S Sokolova
- Department of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Johann P Klare
- Department of Physics, Osnabrueck University, 49069 Osnabrueck, Germany
| | - Armen Y Mulkidjanian
- Department of Physics, Osnabrueck University, 49069 Osnabrueck, Germany; A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia; Department of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Konstantin V Shaitan
- Department of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow 119991, Russia
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Sjodt M, Clubb RT. Nitroxide Labeling of Proteins and the Determination of Paramagnetic Relaxation Derived Distance Restraints for NMR Studies. Bio Protoc 2017; 7:e2207. [PMID: 28616445 DOI: 10.21769/bioprotoc.2207] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Site-specific attachment of paramagnetic spin labels to biomolecules causes distance-dependent line-broadening effects, which can be exploited to study the structure and dynamics of these molecules in solution. This protocol describes how to attach nitroxide spin labels to proteins and how to collect and analyze NMR data using these labeled samples. We also explain how to derive distance restraints for paramagnetic relaxation enhancement nuclear magnetic resonance (PRE-NMR) studies.
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Affiliation(s)
- Megan Sjodt
- Department of Chemistry and Biochemistry, UCLA-DOE Institute of Genomics and Proteomics and Molecular Biology Institute, University of California, Los Angeles, USA
| | - Robert T Clubb
- Department of Chemistry and Biochemistry, UCLA-DOE Institute of Genomics and Proteomics and Molecular Biology Institute, University of California, Los Angeles, USA
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Columbus L, Kroncke B. Solution NMR Structure Determination of Polytopic α-Helical Membrane Proteins: A Guide to Spin Label Paramagnetic Relaxation Enhancement Restraints. Methods Enzymol 2015; 557:329-48. [PMID: 25950972 DOI: 10.1016/bs.mie.2014.12.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Solution nuclear magnetic resonance structures of polytopic α-helical membrane proteins require additional restraints beyond the traditional Nuclear Overhauser Effect (NOE) restraints. Several methods have been developed and this review focuses on paramagnetic relaxation enhancement (PRE). Important aspects of spin labeling, PRE measurements, structure calculations, and structural quality are discussed.
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