1
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Wang B, Tieleman DP. The structure, self-assembly and dynamics of lipid nanodiscs revealed by computational approaches. Biophys Chem 2024; 309:107231. [PMID: 38569455 DOI: 10.1016/j.bpc.2024.107231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/05/2024]
Abstract
Nanodisc technology is increasingly being used in structural, biochemical and biophysical studies of membrane proteins. The computational approaches have revealed many important features of nanodisc assembly, structures and dynamics. Therefore, we reviewed the application of computational approaches, especially molecular modeling and molecular dyncamics (MD) simulations, to characterize nanodiscs, including the structural models, assembly and disassembly, protocols for modeling, structural properties and dynamics, and protein-lipid interactions in nanodiscs. More amazing computational studies about nanodiscs are looked forward to in the future.
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Affiliation(s)
- Beibei Wang
- Centre for Advanced Materials Research, Beijing Normal University, Zhuhai 519087, China.
| | - D Peter Tieleman
- Department of Biological Sciences and Centre for Molecular Simulation, University of Calgary, Calgary T2N 1N4, Canada.
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2
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Nady A, Reichheld SE, Sharpe S. Structural studies of a serum amyloid A octamer that is primed to scaffold lipid nanodiscs. Protein Sci 2024; 33:e4983. [PMID: 38659173 PMCID: PMC11043621 DOI: 10.1002/pro.4983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/21/2024] [Accepted: 03/22/2024] [Indexed: 04/26/2024]
Abstract
Serum amyloid A (SAA) is a highly conserved acute-phase protein that plays roles in activating multiple pro-inflammatory pathways during the acute inflammatory response and is commonly used as a biomarker of inflammation. It has been linked to beneficial roles in tissue repair through improved clearance of lipids and cholesterol from sites of damage. In patients with chronic inflammatory diseases, elevated levels of SAA may contribute to increased severity of the underlying condition. The majority of circulating SAA is bound to lipoproteins, primarily high-density lipoprotein (HDL). Interaction with HDL not only stabilizes SAA but also alters its functional properties, likely through altered accessibility of protein-protein interaction sites on SAA. While high-resolution structures for lipid-free, or apo-, forms of SAA have been reported, their relationship with the HDL-bound form of the protein, and with other possible mechanisms of SAA binding to lipids, has not been established. Here, we have used multiple biophysical techniques, including SAXS, TEM, SEC-MALS, native gel electrophoresis, glutaraldehyde crosslinking, and trypsin digestion to characterize the lipid-free and lipid-bound forms of SAA. The SAXS and TEM data show the presence of soluble octamers of SAA with structural similarity to the ring-like structures reported for lipid-free ApoA-I. These SAA octamers represent a previously uncharacterized structure for lipid-free SAA and are capable of scaffolding lipid nanodiscs with similar morphology to those formed by ApoA-I. The SAA-lipid nanodiscs contain four SAA molecules and have similar exterior dimensions as the lipid-free SAA octamer, suggesting that relatively few conformational rearrangements may be required to allow SAA interactions with lipid-containing particles such as HDL. This study suggests a new model for SAA-lipid interactions and provides new insight into how SAA might stabilize protein-lipid nanodiscs or even replace ApoA-I as a scaffold for HDL particles during inflammation.
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Affiliation(s)
- Asal Nady
- Molecular Medicine ProgramThe Hospital for Sick ChildrenTorontoCanada
- Department of BiochemistryUniversity of TorontoTorontoCanada
| | - Sean E. Reichheld
- Molecular Medicine ProgramThe Hospital for Sick ChildrenTorontoCanada
| | - Simon Sharpe
- Molecular Medicine ProgramThe Hospital for Sick ChildrenTorontoCanada
- Department of BiochemistryUniversity of TorontoTorontoCanada
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3
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Smith JW, Carnevale LN, Das A, Chen Q. Electron videography of a lipid-protein tango. SCIENCE ADVANCES 2024; 10:eadk0217. [PMID: 38630809 PMCID: PMC11023515 DOI: 10.1126/sciadv.adk0217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 03/15/2024] [Indexed: 04/19/2024]
Abstract
Biological phenomena, from enzymatic catalysis to synaptic transmission, originate in the structural transformations of biomolecules and biomolecular assemblies in liquid water. However, directly imaging these nanoscopic dynamics without probes or labels has been a fundamental methodological challenge. Here, we developed an approach for "electron videography"-combining liquid phase electron microscopy with molecular modeling-with which we filmed the nanoscale structural fluctuations of individual, suspended, and unlabeled membrane protein nanodiscs in liquid. Systematic comparisons with biochemical data and simulation indicate the graphene encapsulation involved can afford sufficiently reduced effects of the illuminating electron beam for these observations to yield quantitative fingerprints of nanoscale lipid-protein interactions. Our results suggest that lipid-protein interactions delineate dynamically modified membrane domains across unexpectedly long ranges. Moreover, they contribute to the molecular mechanics of the nanodisc as a whole in a manner specific to the protein within. Overall, this work illustrates an experimental approach to film, quantify, and understand biomolecular dynamics at the nanometer scale.
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Affiliation(s)
- John W. Smith
- Department of Materials Science and Engineering, University of Illinois Urbana–Champaign, Urbana, IL 61801, USA
| | - Lauren N. Carnevale
- Department of Biochemistry, University of Illinois Urbana–Champaign, Urbana, IL 61801, USA
| | - Aditi Das
- School of Chemistry and Biochemistry, Parker H. Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Qian Chen
- Department of Materials Science and Engineering, University of Illinois Urbana–Champaign, Urbana, IL 61801, USA
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana–Champaign, Urbana, IL 61801, USA
- Department of Chemistry, University of Illinois Urbana–Champaign, Urbana, IL 61801, USA
- Materials Research Laboratory, University of Illinois Urbana–Champaign, Urbana, IL 61801, USA
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4
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Caron NS, Aly AEE, Findlay Black H, Martin DDO, Schmidt ME, Ko S, Anderson C, Harvey EM, Casal LL, Anderson LM, Rahavi SMR, Reid GSD, Oda MN, Stanimirovic D, Abulrob A, McBride JL, Leavitt BR, Hayden MR. Systemic delivery of mutant huntingtin lowering antisense oligonucleotides to the brain using apolipoprotein A-I nanodisks for Huntington disease. J Control Release 2024; 367:27-44. [PMID: 38215984 DOI: 10.1016/j.jconrel.2024.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 12/09/2023] [Accepted: 01/09/2024] [Indexed: 01/14/2024]
Abstract
Efficient delivery of therapeutics to the central nervous system (CNS) remains a major challenge for the treatment of neurological diseases. Huntington disease (HD) is a dominantly inherited neurodegenerative disorder caused by a CAG trinucleotide expansion mutation in the HTT gene which codes for a toxic mutant huntingtin (mHTT) protein. Pharmacological reduction of mHTT in the CNS using antisense oligonucleotides (ASO) ameliorates HD-like phenotypes in rodent models of HD, with such therapies being investigated in clinical trials for HD. In this study, we report the optimization of apolipoprotein A-I nanodisks (apoA-I NDs) as vehicles for delivery of a HTT-targeted ASO (HTT ASO) to the brain and peripheral organs for HD. We demonstrate that apoA-I wild type (WT) and the apoA-I K133C mutant incubated with a synthetic lipid, 1,2-dimyristoyl-sn-glycero-3-phosphocholine, can self-assemble into monodisperse discoidal particles with diameters <20 nm that transmigrate across an in vitro blood-brain barrier model of HD. We demonstrate that apoA-I NDs are well tolerated in vivo, and that apoA-I K133C NDs show enhanced distribution to the CNS and peripheral organs compared to apoA-I WT NDs following systemic administration. ApoA-I K133C conjugated with HTT ASO forms NDs (HTT ASO NDs) that induce significant mHTT lowering in the liver, skeletal muscle and heart as well as in the brain when delivered intravenously in the BACHD mouse model of HD. Furthermore, HTT ASO NDs increase the magnitude of mHTT lowering in the striatum and cortex compared to HTT ASO alone following intracerebroventricular administration. These findings demonstrate the potential utility of apoA-I NDs as biocompatible vehicles for enhancing delivery of mutant HTT lowering ASOs to the CNS and peripheral organs for HD.
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Affiliation(s)
- Nicholas S Caron
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Amirah E-E Aly
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hailey Findlay Black
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dale D O Martin
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada; Department of Biology, University of Waterloo, Ontario, Canada
| | - Mandi E Schmidt
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Neuroscience, University of British Columbia, Vancouver, British Columbia, Canada
| | - Seunghyun Ko
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada
| | - Christine Anderson
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada
| | - Emily M Harvey
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada
| | - Lorenzo L Casal
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada
| | - Lisa M Anderson
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada
| | - Seyed M R Rahavi
- BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Gregor S D Reid
- BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Danica Stanimirovic
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - Abedelnasser Abulrob
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - Jodi L McBride
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, USA; Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR, USA
| | - Blair R Leavitt
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada.
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5
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Zhou Y, Zhao J, Guo J, Lian X, Wang H. Effects of Amylopectins from Five Different Sources on Disulfide Bond Formation in Alkali-Soluble Glutenin. Foods 2023; 12:foods12020414. [PMID: 36673506 PMCID: PMC9857419 DOI: 10.3390/foods12020414] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/10/2023] [Accepted: 01/10/2023] [Indexed: 01/19/2023] Open
Abstract
Wheat, maize, cassava, mung bean and sweet potato starches have often been added to dough systems to improve their hardness. However, inconsistent effects of these starches on the dough quality have been reported, especially in refrigerated dough. The disulfide bond contents of alkali-soluble glutenin (ASG) have direct effects on the hardness of dough. In this paper, the disulfide bond contents of ASG were determined. ASG was mixed and retrograded with five kinds of amylopectins from the above-mentioned botanical sources, and a possible pathway of disulfide bond formation in ASGs by amylopectin addition was proposed through molecular weight, chain length distribution, FT-IR, 13C solid-state NMR and XRD analyses. The results showed that when wheat, maize, cassava, mung bean and sweet potato amylopectins were mixed with ASG, the disulfide bond contents of alkali-soluble glutenin increased from 0.04 to 0.31, 0.24, 0.08, 0.18 and 0.29 μmol/g, respectively. However, after cold storage, they changed to 0.55, 0.16, 0.26, 0.07 and 0.19 μmol/g, respectively. The addition of wheat amylopectin promoted the most significant disulfide bond formation of ASG. Hydroxyproline only existed in the wheat amylopectin, indicating that it had an important effect on the disulfide bond formation of ASG. Glutathione disulfides were present, as mung bean and sweet potato amylopectin were mixed with ASG, and they were reduced during cold storage. Positive/negative correlations between the peak intensity of the angles at 2θ = 20°/23° and the disulfide bond contents of ASG existed. The high content of hydroxyproline could be used as a marker for breeding high-quality wheat.
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Affiliation(s)
- Yu Zhou
- Tianjin Key Laboratory of Food Biotechnology, School of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin 300134, China
| | - Jinjin Zhao
- Tianjin Key Laboratory of Food Biotechnology, School of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin 300134, China
| | - Junjie Guo
- Tianjin Key Laboratory of Food Biotechnology, School of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin 300134, China
| | - Xijun Lian
- Tianjin Key Laboratory of Food Biotechnology, School of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin 300134, China
- Correspondence: ; Tel.: +86-13-312101772; Fax: +86-22-26686254
| | - Huaiwen Wang
- School of Mechanical Engineering, Tianjin University of Commerce, Tianjin 300134, China
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6
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You X, Thakur N, Ray AP, Eddy MT, Baiz CR. A comparative study of interfacial environments in lipid nanodiscs and vesicles. BIOPHYSICAL REPORTS 2022; 2. [PMID: 36176716 PMCID: PMC9518727 DOI: 10.1016/j.bpr.2022.100066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Membrane protein conformations and dynamics are driven by the protein-lipid interactions occurring within the local environment of the membrane. These environments remain challenging to accurately capture in structural and biophysical experiments using bilayers. Consequently, there is an increasing need for realistic cell-membrane mimetics for in vitro studies. Lipid nanodiscs provide certain advantages over vesicles for membrane protein studies. Nanodiscs are increasingly used for structural and spectroscopic characterization of membrane proteins. Despite the common use of nanodiscs, the interfacial environments of lipids confined to a ~10-nm diameter area have remained relatively underexplored. Here, we use ultrafast two-dimensional infrared spectroscopy and temperature-dependent infrared absorption measurements of the ester carbonyls to compare the interfacial hydrogen bond structure and dynamics in lipid nanodiscs of varying lipid compositions and sizes with ~100-nm vesicles. We examine the effects of lipid composition and nanodisc size. We found that nanodiscs and vesicles share largely similar lipid-water H-bond environments and interfacial dynamics. Differences in measured enthalpies of H-bonding suggest that H-bond dynamics in nanodiscs are modulated by the interaction between the annular lipids and the scaffold protein.
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7
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Sligar SG, Denisov IG. Nanodiscs: A toolkit for membrane protein science. Protein Sci 2020; 30:297-315. [PMID: 33165998 DOI: 10.1002/pro.3994] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 10/30/2020] [Accepted: 10/30/2020] [Indexed: 12/25/2022]
Abstract
Membrane proteins are involved in numerous vital biological processes, including transport, signal transduction and the enzymes in a variety of metabolic pathways. Integral membrane proteins account for up to 30% of the human proteome and they make up more than half of all currently marketed therapeutic targets. Unfortunately, membrane proteins are inherently recalcitrant to study using the normal toolkit available to scientists, and one is most often left with the challenge of finding inhibitors, activators and specific antibodies using a denatured or detergent solubilized aggregate. The Nanodisc platform circumvents these challenges by providing a self-assembled system that renders typically insoluble, yet biologically and pharmacologically significant, targets such as receptors, transporters, enzymes, and viral antigens soluble in aqueous media in a native-like bilayer environment that maintain a target's functional activity. By providing a bilayer surface of defined composition and structure, Nanodiscs have found great utility in the study of cellular signaling complexes that assemble on a membrane surface. Nanodiscs provide a nanometer scale vehicle for the in vivo delivery of amphipathic drugs, therapeutic lipids, tethered nucleic acids, imaging agents and active protein complexes. This means for generating nanoscale lipid bilayers has spawned the successful use of numerous other polymer and peptide amphipathic systems. This review, in celebration of the Anfinsen Award, summarizes some recent results and provides an inroad into the current and historical literature.
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Affiliation(s)
- Stephen G Sligar
- Departments of Biochemistry Chemistry, University of Illinois, Urbana-Champaign, Urbana, Illinois, USA
| | - Ilia G Denisov
- Departments of Biochemistry Chemistry, University of Illinois, Urbana-Champaign, Urbana, Illinois, USA
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8
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Schachter I, Allolio C, Khelashvili G, Harries D. Confinement in Nanodiscs Anisotropically Modifies Lipid Bilayer Elastic Properties. J Phys Chem B 2020; 124:7166-7175. [PMID: 32697588 PMCID: PMC7526989 DOI: 10.1021/acs.jpcb.0c03374] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
![]()
Lipid
nanodiscs are small synthetic lipid bilayer structures that
are stabilized in solution by special circumscribing (or scaffolding)
proteins or polymers. Because they create native-like environments
for transmembrane proteins, lipid nanodiscs have become a powerful
tool for structural determination of this class of systems when combined
with cryo-electron microscopy or nuclear magnetic resonance. The elastic
properties of lipid bilayers determine how the lipid environment responds
to membrane protein perturbations, and how the lipid in turn modifies
the conformational state of the embedded protein. However, despite
the abundant use of nanodiscs in determining membrane protein structure,
the elastic material properties of even pure lipid nanodiscs (i.e.,
without embedded proteins) have not yet been quantitatively investigated.
A major hurdle is due to the inherently nonlocal treatment of the
elastic properties of lipid systems implemented by most existing methods,
both experimental and computational. In addition, these methods are
best suited for very large “infinite” size lipidic assemblies,
or ones that contain periodicity, in the case of simulations. We have
previously described a computational analysis of molecular dynamics
simulations designed to overcome these limitations, so it allows quantification
of the bending rigidity (KC) and tilt
modulus (κt) on a local scale even for finite, nonperiodic
systems, such as lipid nanodiscs. Here we use this computational approach
to extract values of KC and κt for a set of lipid nanodisc systems that vary in size and
lipid composition. We find that the material properties of lipid nanodiscs
are different from those of infinite bilayers of corresponding lipid
composition, highlighting the effect of nanodisc confinement. Nanodiscs
tend to show higher stiffness than their corresponding macroscopic
bilayers, and moreover, their material properties vary spatially within
them. For small-size MSP1 nanodiscs, the stiffness decreases radially,
from a value that is larger in their center than the moduli of the
corresponding bilayers by a factor of ∼2–3. The larger
nanodiscs (MSP1E3D1 and MSP2N2) show milder spatial changes of moduli
that are composition dependent and can be maximal in the center or
at some distance from it. These trends in moduli correlate with spatially
varying structural properties, including the area per lipid and the
nanodisc thickness. Finally, as has previously been reported, nanodiscs
tend to show deformations from perfectly flat circular geometries
to varying degrees, depending on size and lipid composition. The modulations
of lipid elastic properties that we find should be carefully considered
when making structural and functional inferences concerning embedded
proteins.
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Affiliation(s)
- Itay Schachter
- Institute of Chemistry, the Fritz Haber Research Center, and the Harvey M. Kruger center for Nanoscience & Nanotechnology, The Hebrew University, Jerusalem 9190401, Israel
| | - Christoph Allolio
- Institute of Mathematics, Faculty of Mathematics and Physics, Charles University, Prague 18674, Czech Republic
| | - George Khelashvili
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, New York 10065, United States.,Institute for Computational Biomedicine, Weill Cornell Medical College of Cornell University, New York, New York 10065, United States
| | - Daniel Harries
- Institute of Chemistry, the Fritz Haber Research Center, and the Harvey M. Kruger center for Nanoscience & Nanotechnology, The Hebrew University, Jerusalem 9190401, Israel
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9
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Abstract
The interactions between lipids and proteins are one of the most fundamental processes in living organisms, responsible for critical cellular events ranging from replication, cell division, signaling, and movement. Enabling the central coupling responsible for maintaining the functionality of the breadth of proteins, receptors, and enzymes that find their natural home in biological membranes, the fundamental mechanisms of recognition of protein for lipid, and vice versa, have been a focal point of biochemical and biophysical investigations for many decades. Complexes of lipids and proteins, such as the various lipoprotein factions, play central roles in the trafficking of important proteins, small molecules and metabolites and are often implicated in disease states. Recently an engineered lipoprotein particle, termed the nanodisc, a modified form of the human high density lipoprotein fraction, has served as a membrane mimetic for the investigation of membrane proteins and studies of lipid-protein interactions. In this review, we summarize the current knowledge regarding this self-assembling lipid-protein complex and provide examples for its utility in the investigation of a large number of biological systems.
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10
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Minimal nanodisc without exogenous lipids for stabilizing membrane proteins in detergent-free buffer. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:852-860. [DOI: 10.1016/j.bbamem.2019.01.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 12/17/2018] [Accepted: 01/24/2019] [Indexed: 01/29/2023]
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11
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Qi Y, Lee J, Klauda JB, Im W. CHARMM-GUI Nanodisc Builder for modeling and simulation of various nanodisc systems. J Comput Chem 2019; 40:893-899. [PMID: 30677169 DOI: 10.1002/jcc.25773] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 12/05/2018] [Accepted: 12/11/2018] [Indexed: 01/13/2023]
Abstract
Nanodiscs are discoidal protein-lipid complexes that have wide applications in membrane protein studies. Modeling and simulation of nanodiscs are challenging due to the absence of structures of many membrane scaffold proteins (MSPs) that wrap around the membrane bilayer. We have developed CHARMM-GUI Nanodisc Builder (http://www.charmm-gui.org/input/nanodisc) to facilitate the setup of nanodisc simulation systems by modeling the MSPs with defined size and known structural features. A total of 11 different nanodiscs with a diameter from 80 to 180 Å are made available in both the all-atom CHARMM and two coarse-grained (PACE and Martini) force fields. The usage of the Nanodisc Builder is demonstrated with various simulation systems. The structures and dynamics of proteins and lipids in these systems were analyzed, showing similar behaviors to those from previous all-atom and coarse-grained nanodisc simulations. We expect the Nanodisc Builder to be a convenient and reliable tool for modeling and simulation of nanodisc systems. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Yifei Qi
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China
| | - Jumin Lee
- Departments of Biological Sciences and Bioengineering, Lehigh University, Bethlehem, Pennsylvania
| | - Jeffery B Klauda
- Department of Chemical and Biomolecular Engineering and the Biophysics Program, University of Maryland, College Park, Maryland
| | - Wonpil Im
- Departments of Biological Sciences and Bioengineering, Lehigh University, Bethlehem, Pennsylvania
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12
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Kawanobe T, Shiranaga N, Kioka N, Kimura Y, Ueda K. Apolipoprotein A-I directly interacts with extracellular domain 1 of human ABCA1. Biosci Biotechnol Biochem 2019; 83:490-497. [DOI: 10.1080/09168451.2018.1547106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
ABSTRACT
ATP-binding cassette transporter A1 (ABCA1) is critical for the generation of nascent high-density lipoprotein (HDL) and plays important roles in cholesterol homeostasis. ABCA1 has two large extracellular domains (ECDs), which may interact directly with apolipoprotein A-I (apoA-I). However, the molecular mechanisms underlying HDL formation and the importance of ABCA1–apoA-I interactions in HDL formation remain unclear. We investigated the ABCA1–apoA-I interaction in photo-activated crosslinking experiments using sulfo-SBED–labeled apoA-I. ApoA-I bound to cells expressing ABCA1, but not to untransfected cells or cells expressing non-functional ABCA1. Binding was inhibited by sulfo-SBED–labeled apoA-I, and crosslinking of sulfo-SBED–labeled apoA-I with ABCA1 was inhibited by non-labeled apoA-I, suggesting that sulfo-SBED–labeled apoA-I specifically binds and crosslinks with functional ABCA1. Proteolytic digestion of crosslinked ABCA1 revealed that apoA-I bound the N-terminal half of ABCA1, and that the first ECD of ABCA1 is an apoA-I binding site.
Abbreviations: ABC: ATP-binding cassette; apoA-I: apolipoprotein A-I; ATP: adenosine triphosphate; CHAPS: 3-(3-cholamidepropyl)dimethylammonio-1- propanesulphonate; DTT: dithiothreitol; ECD: extra cellular domain; EDTA: ethylenediaminetetraacetic acid; GFP: green fluorescent protein; HA: hemagglutinin; HDL: high density lipoprotein; HEK: human embryonic kidney; HEPES: 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid; sulfo-SBED: (sulfosuccinimidyl-2-[6-(biotinamido)-2-(p-azidobenzamido)hexanoamido] ethyl-1,3ʹ-dithiopropionate; NHS-ester, N-hydroxysuccinimide-ester
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Affiliation(s)
- Takaaki Kawanobe
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Naoko Shiranaga
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Noriyuki Kioka
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto, Japan
| | - Yasuhisa Kimura
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Kazumitsu Ueda
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto, Japan
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13
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Salnikov ES, Aisenbrey C, Anantharamaiah G, Bechinger B. Solid-state NMR structural investigations of peptide-based nanodiscs and of transmembrane helices in bicellar arrangements. Chem Phys Lipids 2019; 219:58-71. [DOI: 10.1016/j.chemphyslip.2019.01.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 01/29/2019] [Accepted: 01/29/2019] [Indexed: 02/08/2023]
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14
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Camp T, McLean M, Kato M, Cheruzel L, Sligar S. The hydrodynamic motion of Nanodiscs. Chem Phys Lipids 2019; 220:28-35. [PMID: 30802435 DOI: 10.1016/j.chemphyslip.2019.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 02/20/2019] [Accepted: 02/21/2019] [Indexed: 02/02/2023]
Abstract
We present a fluorescence-based methodology for monitoring the rotational dynamics of Nanodiscs. Nanodiscs are nano-scale lipid bilayers surrounded by a helical membrane scaffold protein (MSP) that have found considerable use in studying the interactions between membrane proteins and their lipid bilayer environment. Using a long-lifetime Ruthenium label covalently attached to the Nanodiscs, we find that Nanodiscs of increasing diameter, made by varying the number of helical repeats in the MSP, display increasing rotational correlation times. We also model our system using both analytical equations that describe rotating spheroids and numerical calculations performed on atomic models of Nanodiscs. Using these methods, we observe a linear relationship between the experimentally determined rotational correlation times and those calculated from both analytical equations and numerical solutions. This work sets the stage for accurate, label-free quantification of protein-lipid interactions at the membrane surface.
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Affiliation(s)
- Tyler Camp
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, 314F Roger Adams Laboratory (MC-712), 600 S Mathews Ave, Urbana, IL, 61801, United States; Department of Biochemistry, University of Illinois at Urbana-Champaign, 417 RAL (MC-712), 600 South Mathews Avenue, Urbana, IL, 61801, United States
| | - Mark McLean
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 417 RAL (MC-712), 600 South Mathews Avenue, Urbana, IL, 61801, United States
| | - Mallory Kato
- Department of Chemistry, San Jose State University, San Jose, CA, 95192-0101, United States
| | - Lionel Cheruzel
- Department of Chemistry, San Jose State University, San Jose, CA, 95192-0101, United States
| | - Stephen Sligar
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, 314F Roger Adams Laboratory (MC-712), 600 S Mathews Ave, Urbana, IL, 61801, United States; Department of Biochemistry, University of Illinois at Urbana-Champaign, 417 RAL (MC-712), 600 South Mathews Avenue, Urbana, IL, 61801, United States.
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Overduin M, Esmaili M. Memtein: The fundamental unit of membrane-protein structure and function. Chem Phys Lipids 2019; 218:73-84. [DOI: 10.1016/j.chemphyslip.2018.11.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 11/24/2018] [Accepted: 11/28/2018] [Indexed: 12/14/2022]
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16
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Henrich E, Löhr F, Mezhyrova J, Laguerre A, Bernhard F, Dötsch V. Synthetic Biology-Based Solution NMR Studies on Membrane Proteins in Lipid Environments. Methods Enzymol 2018; 614:143-185. [PMID: 30611423 DOI: 10.1016/bs.mie.2018.08.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Although membrane proteins are in the focus of biochemical research for many decades the general knowledge of this important class is far behind soluble proteins. Despite several recent technical developments, the most challenging feature still is the generation of high-quality samples in environments suitable for the selected application. Reconstitution of membrane proteins into lipid bilayers will generate the most native-like environment and is therefore commonly desired. However, it poses tremendous problems to solution-state NMR analysis due to the dramatic increase in particle size resulting in high rotational correlation times. Nevertheless, a few promising strategies for the solution NMR analysis of membrane inserted proteins are emerging and will be discussed in this chapter. We focus on the generation of membrane protein samples in nanodisc membranes by cell-free systems and will describe the characteristic advantages of that platform in providing tailored protein expression and folding environments. We indicate frequent problems that have to be overcome in cell-free synthesis, nanodisc preparation, and customization for samples dedicated for solution-state NMR. Detailed instructions for sample preparation are given, and solution NMR approaches suitable for membrane proteins in bilayers are compiled. We further discuss the current strategies applied for signal detection from such difficult samples and describe the type of information that can be extracted from the various experiments. In summary, a comprehensive guideline for the analysis of membrane proteins in native-like membrane environments by solution-state NMR techniques will be provided.
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Affiliation(s)
- Erik Henrich
- Institute of Biophysical Chemistry, Centre for Biomolecular Magnetic Resonance, J.W. Goethe-University, Frankfurt am Main, Germany
| | - Frank Löhr
- Institute of Biophysical Chemistry, Centre for Biomolecular Magnetic Resonance, J.W. Goethe-University, Frankfurt am Main, Germany
| | - Julija Mezhyrova
- Institute of Biophysical Chemistry, Centre for Biomolecular Magnetic Resonance, J.W. Goethe-University, Frankfurt am Main, Germany
| | - Aisha Laguerre
- Institute of Biophysical Chemistry, Centre for Biomolecular Magnetic Resonance, J.W. Goethe-University, Frankfurt am Main, Germany
| | - Frank Bernhard
- Institute of Biophysical Chemistry, Centre for Biomolecular Magnetic Resonance, J.W. Goethe-University, Frankfurt am Main, Germany
| | - Volker Dötsch
- Institute of Biophysical Chemistry, Centre for Biomolecular Magnetic Resonance, J.W. Goethe-University, Frankfurt am Main, Germany.
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Supramolecular Organization of Apolipoprotein-A-I-Derived Peptides within Disc-like Arrangements. Biophys J 2018; 115:467-477. [PMID: 30054032 DOI: 10.1016/j.bpj.2018.06.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 06/18/2018] [Accepted: 06/20/2018] [Indexed: 01/05/2023] Open
Abstract
Apolipoprotein A-I is the major protein component of high-density lipoproteins and fulfils important functions in lipid metabolism. Its structure consists of a chain of tandem domains of amphipathic helices. Using this protein as a template membrane scaffolding protein, class A amphipathic helical peptides were designed to support the amphipathic helix theory and later as therapeutic tools in biomedicine. Here, we investigated the lipid interactions of two apolipoprotein-A-I-derived class A amphipathic peptides, 14A (Ac-DYLKA FYDKL KEAF-NH2) and 18A (Ac-DWLKA FYDKV AEKLK EAF- NH2), including the disc-like supramolecular structures they form with phospholipids. Thus, the topologies of 14A and 18A in phospholipid bilayers have been determined by oriented solid-state NMR spectroscopy. Whereas at a peptide-to-lipid ratio of 2 mol% the peptides align parallel to the bilayer surface, at 7.5 mol% disc-like structures are formed that spontaneously orient in the magnetic field of the NMR spectrometer. From a comprehensive data set of four 15N- or 2H-labeled positions of 14A, a tilt angle, which deviates from perfectly in-planar by 14°, and a model for the peptidic rim structure have been obtained. The tilt and helical pitch angles are well suited to cover the hydrophobic chain region of the bilayer when two peptide helices form a head-to-tail dimer. Thus, the detailed topology found in this work agrees with the peptides forming the rim of nanodiscs in a double belt arrangement.
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18
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Mio K, Sato C. Lipid environment of membrane proteins in cryo-EM based structural analysis. Biophys Rev 2018; 10:307-316. [PMID: 29256118 PMCID: PMC5899730 DOI: 10.1007/s12551-017-0371-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 11/20/2017] [Indexed: 12/18/2022] Open
Abstract
Cryoelectron microscopy (cryo-EM) in association with a single particle analysis method (SPA) is now a promising tool to determine the structures of proteins and their macromolecular complexes. The development of direct electron detection cameras and image processing technologies has allowed the structures of many important proteins to be solved at near-atomic resolution or, in some cases, at atomic resolution, by overcoming difficulties in crystallization or low yield of protein production. In the case of membrane-integrated proteins, the proteins were traditionally solubilized and stabilized with various kind of detergents. However, the density of detergent micelles diminished the contrast of membrane proteins in cryo-EM studies and made it difficult to obtain high-resolution structures. To improve the resolution of membrane protein structures in cryo-EM studies, major improvements have been made both in sample preparation techniques and in hardware and software developments. The focus of our review is on improvements which have been made in the various techniques for sample preparation for cryo-EM studies, with a specific interest placed on techniques for mimicking the lipid environment of membrane proteins.
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Affiliation(s)
- Kazuhiro Mio
- AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Chiba, 277-8568, Japan.
- Molecular Profiling Research Center for Drug Discovery (molprof), National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, 135-0064, Japan.
| | - Chikara Sato
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8566, Japan.
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McLean MA, Gregory MC, Sligar SG. Nanodiscs: A Controlled Bilayer Surface for the Study of Membrane Proteins. Annu Rev Biophys 2018; 47:107-124. [PMID: 29494254 DOI: 10.1146/annurev-biophys-070816-033620] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The study of membrane proteins and receptors presents many challenges to researchers wishing to perform biophysical measurements to determine the structure, function, and mechanism of action of such components. In most cases, to be fully functional, proteins and receptors require the presence of a native phospholipid bilayer. In addition, many complex multiprotein assemblies involved in cellular communication require an integral membrane protein as well as a membrane surface for assembly and information transfer to soluble partners in a signaling cascade. Incorporation of membrane proteins into Nanodiscs renders the target soluble and provides a native bilayer environment with precisely controlled composition of lipids, cholesterol, and other components. Likewise, Nanodiscs provide a surface of defined area useful in revealing lipid specificity and affinities for the assembly of signaling complexes. In this review, we highlight several biophysical techniques made possible through the use of Nanodiscs.
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Affiliation(s)
- Mark A McLean
- Department of Biochemistry, University of Illinois, Urbana, Illinois 61801, USA; , ,
| | - Michael C Gregory
- Department of Biochemistry, University of Illinois, Urbana, Illinois 61801, USA; , ,
| | - Stephen G Sligar
- Department of Biochemistry, University of Illinois, Urbana, Illinois 61801, USA; , ,
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20
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Martinez D, Decossas M, Kowal J, Frey L, Stahlberg H, Dufourc EJ, Riek R, Habenstein B, Bibow S, Loquet A. Lipid Internal Dynamics Probed in Nanodiscs. Chemphyschem 2017; 18:2651-2657. [PMID: 28573816 PMCID: PMC5697661 DOI: 10.1002/cphc.201700450] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Indexed: 11/29/2022]
Abstract
Nanodiscs offer a very promising tool to incorporate membrane proteins into native-like lipid bilayers and an alternative to liposomes to maintain protein functions and protein-lipid interactions in a soluble nanoscale object. The activity of the incorporated membrane protein appears to be correlated to its dynamics in the lipid bilayer and by protein-lipid interactions. These two parameters depend on the lipid internal dynamics surrounded by the lipid-encircling discoidal scaffold protein that might differ from more unrestricted lipid bilayers observed in vesicles or cellular extracts. A solid-state NMR spectroscopy investigation of lipid internal dynamics and thermotropism in nanodiscs is reported. The gel-to-fluid phase transition is almost abolished for nanodiscs, which maintain lipid fluid properties for a large temperature range. The addition of cholesterol allows fine-tuning of the internal bilayer dynamics by increasing chain ordering. Increased site-specific order parameters along the acyl chain reflect a higher internal ordering in nanodiscs compared with liposomes at room temperature; this is induced by the scaffold protein, which restricts lipid diffusion in the nanodisc area.
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Affiliation(s)
- Denis Martinez
- CBMNCNRS.University of BordeauxIECBAll. Geoffroy Saint-Hilaire34600PessacFrance
| | - Marion Decossas
- CBMNCNRS.University of BordeauxIECBAll. Geoffroy Saint-Hilaire34600PessacFrance
| | - Julia Kowal
- D C-CINAUniversity of Basel4058BaselSwitzerland
| | - Lukas Frey
- Laboratory for Physical ChemistryETH Zürich8093ZürichSwitzerland
| | | | - Erick J. Dufourc
- CBMNCNRS.University of BordeauxIECBAll. Geoffroy Saint-Hilaire34600PessacFrance
| | - Roland Riek
- Laboratory for Physical ChemistryETH Zürich8093ZürichSwitzerland
| | - Birgit Habenstein
- CBMNCNRS.University of BordeauxIECBAll. Geoffroy Saint-Hilaire34600PessacFrance
| | - Stefan Bibow
- BiozentrumUniversity of Basel4058BaselSwitzerland
| | - Antoine Loquet
- CBMNCNRS.University of BordeauxIECBAll. Geoffroy Saint-Hilaire34600PessacFrance
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Lakomek NA, Frey L, Bibow S, Böckmann A, Riek R, Meier BH. Proton-Detected NMR Spectroscopy of Nanodisc-Embedded Membrane Proteins: MAS Solid-State vs Solution-State Methods. J Phys Chem B 2017; 121:7671-7680. [PMID: 28737919 DOI: 10.1021/acs.jpcb.7b06944] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The structural and dynamical characterization of membrane proteins in a lipid bilayer at physiological pH and temperature and free of crystal constraints is crucial for the elucidation of a structure/dynamics-activity relationship. Toward this aim, we explore here the properties of the outer-membrane protein OmpX embedded in lipid bilayer nanodiscs using proton-detected magic angle spinning (MAS) solid-state NMR at 60 and 110 kHz. [1H,15N]-correlation spectra overlay well with the corresponding solution-state NMR spectra. Line widths as well as line intensities in solid and solution both depend critically on the sample temperature and, in particular, on the crossing of the lipid phase transition temperature. MAS (110 kHz) experiments yield well-resolved NMR spectra also for fully protonated OmpX and both below and above the lipid phase transition temperature.
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Affiliation(s)
| | - Lukas Frey
- ETH Zürich , Physical Chemistry, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Stefan Bibow
- ETH Zürich , Physical Chemistry, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Anja Böckmann
- Institut de Biologie et Chimie des Protéines, Bases Moléculaires et Structurales des Systèmes Infectieux, Labex Ecofect, UMR 5086 CNRS, Université de Lyon , 7 passage du Vercors, 69367 Lyon, France
| | - Roland Riek
- ETH Zürich , Physical Chemistry, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Beat H Meier
- ETH Zürich , Physical Chemistry, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
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22
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Abstract
Membrane proteins play a most important part in metabolism, signaling, cell motility, transport, development, and many other biochemical and biophysical processes which constitute fundamentals of life on the molecular level. Detailed understanding of these processes is necessary for the progress of life sciences and biomedical applications. Nanodiscs provide a new and powerful tool for a broad spectrum of biochemical and biophysical studies of membrane proteins and are commonly acknowledged as an optimal membrane mimetic system that provides control over size, composition, and specific functional modifications on the nanometer scale. In this review we attempted to combine a comprehensive list of various applications of nanodisc technology with systematic analysis of the most attractive features of this system and advantages provided by nanodiscs for structural and mechanistic studies of membrane proteins.
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Affiliation(s)
- Ilia G Denisov
- Department of Biochemistry and Department of Chemistry, University of Illinois , Urbana, Illinois 61801, United States
| | - Stephen G Sligar
- Department of Biochemistry and Department of Chemistry, University of Illinois , Urbana, Illinois 61801, United States
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23
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The power, pitfalls and potential of the nanodisc system for NMR-based studies. Biol Chem 2016; 397:1335-1354. [DOI: 10.1515/hsz-2016-0224] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 07/19/2016] [Indexed: 12/21/2022]
Abstract
Abstract
The choice of a suitable membrane mimicking environment is of fundamental importance for the characterization of structure and function of membrane proteins. In this respect, usage of the lipid bilayer nanodisc technology provides a unique potential for nuclear magnetic resonance (NMR)-based studies. This review summarizes the recent advances in this field, focusing on (i) the strengths of the system, (ii) the bottlenecks that may be faced, and (iii) promising capabilities that may be explored in future studies.
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24
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Nanodiscs for structural and functional studies of membrane proteins. Nat Struct Mol Biol 2016; 23:481-6. [PMID: 27273631 DOI: 10.1038/nsmb.3195] [Citation(s) in RCA: 321] [Impact Index Per Article: 40.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 02/24/2016] [Indexed: 12/12/2022]
Abstract
Membrane proteins have long presented a challenge to biochemical and functional studies. In the absence of a bilayer environment, individual proteins and critical macromolecular complexes may be insoluble and may display altered or absent activities. Nanodisc technology provides important advantages for the isolation, purification, structural resolution and functional characterization of membrane proteins. In addition, the ability to precisely control the nanodisc composition provides a nanoscale membrane surface for investigating molecular recognition events.
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25
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Affiliation(s)
- Iwona Siuda
- Department of Biological
Sciences and Centre for Molecular Simulation, University of Calgary, 2500 University Drive North West, Calgary, Alberta T2N 1N4, Canada
| | - D. Peter Tieleman
- Department of Biological
Sciences and Centre for Molecular Simulation, University of Calgary, 2500 University Drive North West, Calgary, Alberta T2N 1N4, Canada
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26
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Malhotra K, Alder NN. Advances in the use of nanoscale bilayers to study membrane protein structure and function. Biotechnol Genet Eng Rev 2015; 30:79-93. [PMID: 25023464 DOI: 10.1080/02648725.2014.921502] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Within the last decade, nanoscale lipid bilayers have emerged as powerful experimental systems in the analysis of membrane proteins (MPs) for both basic and applied research. These discoidal lipid lamellae are stabilized by annuli of specially engineered amphipathic polypeptides (nanodiscs) or polymers (SMALPs/Lipodisqs®). As biomembrane mimetics, they are well suited for the reconstitution of MPs within a controlled lipid environment. Moreover, because they are water-soluble, they are amenable to solution-based biochemical and biophysical experimentation. Hence, due to their solubility, size, stability, and monodispersity, nanoscale lipid bilayers offer technical advantages over more traditional MP analytic approaches such as detergent solubilization and reconstitution into lipid vesicles. In this article, we review some of the most recent advances in the synthesis of polypeptide- and polymer-bound nanoscale lipid bilayers and their application in the study of MP structure and function.
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Affiliation(s)
- Ketan Malhotra
- a Department of Molecular and Cell Biology , University of Connecticut , Storrs , CT 06269 , USA
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27
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Debnath A, Schäfer LV. Structure and Dynamics of Phospholipid Nanodiscs from All-Atom and Coarse-Grained Simulations. J Phys Chem B 2015; 119:6991-7002. [PMID: 25978497 DOI: 10.1021/acs.jpcb.5b02101] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigated structural and dynamical properties of nanodiscs comprising dimyristoylphosphatidylcholine (DMPC) lipids and major scaffold protein MSP1Δ(1-22) from human apolipoprotein A-1 using combined all-atom and coarse-grained (CG) molecular dynamics (MD) simulations. The computational efficiency of the Martini-CG force field enables the spontaneous self-assembly of lipids and scaffold proteins into stable nanodisc structures on time scales up to tens of microseconds. Subsequent all-atom and CG-MD simulations reveal that the lipids in the nanodisc have lower configurational entropy and higher acyl tail order than in a lamellar bilayer phase. These altered average properties arise from rather differential behavior of lipids, depending on their location in the nanodisc. Since the scaffold proteins exert constrictive forces from the outer rim of the disc toward its center, lipids at the center of the nanodisc are highly ordered, whereas annular lipids that are in contact with the MSP proteins are remarkably disordered due to perturbed packing. Although specific differences between all-atom and CG simulations are also evident, the results obtained at both levels of resolution are in overall good agreement with each other and provide atomic level interpretations of recent experiments. Thus, the present study highlights the applicability of multiscale simulation approaches for nanodisc systems and opens the way for future applications, including the study of nanodisc-embedded membrane proteins.
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Affiliation(s)
- Ananya Debnath
- †Department of Chemistry, Indian Institute of Technology Jodhpur, Jodhpur 342 011, India
| | - Lars V Schäfer
- ‡Lehrstuhl für Theoretische Chemie, Ruhr-University Bochum, D-44780 Bochum, Germany
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28
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Ding Y, Fujimoto LM, Yao Y, Marassi FM. Solid-state NMR of the Yersinia pestis outer membrane protein Ail in lipid bilayer nanodiscs sedimented by ultracentrifugation. JOURNAL OF BIOMOLECULAR NMR 2015; 61:275-86. [PMID: 25578899 PMCID: PMC4398618 DOI: 10.1007/s10858-014-9893-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 12/20/2014] [Indexed: 05/22/2023]
Abstract
Solid-state NMR studies of sedimented soluble proteins has been developed recently as an attractive approach for overcoming the size limitations of solution NMR spectroscopy while bypassing the need for sample crystallization or precipitation (Bertini et al. Proc Natl Acad Sci USA 108(26):10396-10399, 2011). Inspired by the potential benefits of this method, we have investigated the ability to sediment lipid bilayer nanodiscs reconstituted with a membrane protein. In this study, we show that nanodiscs containing the outer membrane protein Ail from Yersinia pestis can be sedimented for solid-state NMR structural studies, without the need for precipitation or lyophilization. Optimized preparations of Ail in phospholipid nanodiscs support both the structure and the fibronectin binding activity of the protein. The same sample can be used for solution NMR, solid-state NMR and activity assays, facilitating structure-activity correlation experiments across a wide range of timescales.
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Affiliation(s)
- Yi Ding
- Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla CA 92037, USA
| | - L. Miya Fujimoto
- Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla CA 92037, USA
| | - Yong Yao
- Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla CA 92037, USA
| | - Francesca M. Marassi
- Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla CA 92037, USA
- Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla CA 92037, USA. [Tel: 858-795-5282; Mail: ]
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29
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Das BB, Park SH, Opella SJ. Membrane protein structure from rotational diffusion. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1848:229-45. [PMID: 24747039 PMCID: PMC4201901 DOI: 10.1016/j.bbamem.2014.04.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 04/02/2014] [Indexed: 02/02/2023]
Abstract
The motional averaging of powder pattern line shapes is one of the most fundamental aspects of sold-state NMR. Since membrane proteins in liquid crystalline phospholipid bilayers undergo fast rotational diffusion, all of the signals reflect the angles of the principal axes of their dipole-dipole and chemical shift tensors with respect to the axis defined by the bilayer normal. The frequency span and sign of the axially symmetric powder patterns that result from motional averaging about a common axis provide sufficient structural restraints for the calculation of the three-dimensional structure of a membrane protein in a phospholipid bilayer environment. The method is referred to as rotationally aligned (RA) solid-state NMR and demonstrated with results on full-length, unmodified membrane proteins with one, two, and seven trans-membrane helices. RA solid-state NMR is complementary to other solid-state NMR methods, in particular oriented sample (OS) solid-state NMR of stationary, aligned samples. Structural distortions of membrane proteins from the truncations of terminal residues and other sequence modifications, and the use of detergent micelles instead of phospholipid bilayers have also been demonstrated. Thus, it is highly advantageous to determine the structures of unmodified membrane proteins in liquid crystalline phospholipid bilayers under physiological conditions. RA solid-state NMR provides a general method for obtaining accurate and precise structures of membrane proteins under near-native conditions.
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Affiliation(s)
- Bibhuti B Das
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093-0307 USA
| | - Sang Ho Park
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093-0307 USA
| | - Stanley J Opella
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093-0307 USA.
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30
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Hu A, Fan TH, Katsaras J, Xia Y, Li M, Nieh MP. Lipid-based nanodiscs as models for studying mesoscale coalescence--a transport limited case. SOFT MATTER 2014; 10:5055-5060. [PMID: 24691415 DOI: 10.1039/c3sm51761f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Lipid-based nanodiscs (bicelles) are able to form in mixtures of long- and short-chain lipids. Initially, they are of uniform size but grow upon dilution. Previously, nanodisc growth kinetics have been studied using time-resolved small angle neutron scattering (SANS), a technique which is not well suited for probing their change in size immediately after dilution. To address this, we have used dynamic light scattering (DLS), a technique which permits the collection of useful data in a short span of time after dilution of the system. The DLS data indicate that the negatively charged lipids in nanodiscs play a significant role in disc stability and growth. Specifically, the charged lipids are most likely drawn out from the nanodiscs into solution, thereby reducing interparticle repulsion and enabling the discs to grow. We describe a population balance model, which takes into account Coulombic interactions and adequately predicts the initial growth of nanodiscs with a single parameter - i.e., surface potential. The results presented here strongly support the notion that the disc coalescence rate strongly depends on nanoparticle charge density. The present system containing low-polydispersity lipid nanodiscs serves as a good model for understanding how charged discoidal micelles coalesce.
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Affiliation(s)
- Andrew Hu
- Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269-3139, USA
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31
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Mörs K, Roos C, Scholz F, Wachtveitl J, Dötsch V, Bernhard F, Glaubitz C. Modified lipid and protein dynamics in nanodiscs. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:1222-9. [DOI: 10.1016/j.bbamem.2012.12.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 12/04/2012] [Accepted: 12/11/2012] [Indexed: 02/09/2023]
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32
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ABCA1 dimer-monomer interconversion during HDL generation revealed by single-molecule imaging. Proc Natl Acad Sci U S A 2013; 110:5034-9. [PMID: 23479619 DOI: 10.1073/pnas.1220703110] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The generation of high-density lipoprotein (HDL), one of the most critical events for preventing atherosclerosis, is mediated by ATP-binding cassette protein A1 (ABCA1). ABCA1 is known to transfer cellular cholesterol and phospholipids to apolipoprotein A-I (apoA-I) for generating discoidal HDL (dHDL) particles, composed of 100-200 lipid molecules surrounded by two apoA-I molecules; however, the regulatory mechanisms are still poorly understood. Here we observed ABCA1-GFP and apoA-I at the level of single molecules on the plasma membrane via a total internal reflection fluorescence microscope. We found that about 70% of total ABCA1-GFP spots are immobilized on the plasma membrane and estimated that about 89% of immobile ABCA1 molecules are in dimers. Furthermore, an ATPase-deficient ABCA1 mutant failed to be immobilized or form a dimer. We found that the lipid acceptor apoA-I interacts with the ABCA1 dimer to generate dHDL and is followed by ABCA1 dimer-monomer interconversion. This indicates that the formation of the ABCA1 dimer is the key for apoA-I binding and nascent HDL generation. Our findings suggest the physiological significance of conversion of the ABCA1 monomer to a dimer: The dimer serves as a receptor for two apoA-I molecules for dHDL particle generation.
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33
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Abstract
Solid-state NMR spectroscopy proved to be a versatile tool for characterization of structure and dynamics of complex biochemical systems. In particular, magic angle spinning (MAS) solid-state NMR came to maturity for application towards structural elucidation of biological macromolecules. Current challenges in applying solid-state NMR as well as progress achieved recently will be discussed in the following chapter focusing on conceptual aspects important for structural elucidation of proteins.
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Affiliation(s)
- Henrik Müller
- Institute of Physical Biology, Heinrich-Heine-University of Düsseldorf, 40225, Düsseldorf, Germany
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Abstract
Nanodiscs are self-assembled discoidal fragments of lipid bilayers 8-16 nm in diameter, stabilized in solution by two amphipathic helical scaffold proteins. As stable and highly soluble membrane mimetics with controlled lipid composition and ability to add affinity tags to the scaffold protein, nanodiscs represent an attractive model system for solubilization, isolation, purification, and biophysical and biochemical studies of membrane proteins. In this chapter we overview various approaches to structural and functional studies of different classes of integral membrane proteins such as ion channels, transporters, GPCR and other receptors, membrane enzymes, and blood coagulation cascade proteins which have been incorporated into nanodiscs. We outline the advantages provided by homogeneity, ability to control oligomerization state of the target protein and lipid composition of the bilayer. Special attention is paid to the opportunities afforded by nanodisc system for the detailed studies of the role of different lipid properties and protein-lipid interactions in the functional behavior of membrane proteins.
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Affiliation(s)
- Mary A. Schuler
- Department of Biochemistry, University of Illinois, Urbana, IL 61801 USA
- Department of Cell and Developmental Biology, University of Illinois, Urbana, IL 61801 USA
| | - Ilia G. Denisov
- Department of Biochemistry, University of Illinois, Urbana, IL 61801 USA
| | - Stephen G. Sligar
- Department of Biochemistry, University of Illinois, Urbana, IL 61801 USA
- Department of Chemistry, University of Illinois, Urbana, IL 61801 USA
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35
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Park SH, Berkamp S, Cook GA, Chan MK, Viadiu H, Opella SJ. Nanodiscs versus macrodiscs for NMR of membrane proteins. Biochemistry 2011; 50:8983-5. [PMID: 21936505 DOI: 10.1021/bi201289c] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It is challenging to find membrane mimics that stabilize the native structures, dynamics, and functions of membrane proteins. In a recent advance, nanodiscs have been shown to provide a bilayer environment compatible with solution NMR. We show that increasing the lipid to "belt" peptide ratio expands their diameter, slows their reorientation rate, and allows the protein-containing discs to be aligned in a magnetic field for oriented sample solid-state NMR. The spectroscopic properties of membrane proteins with one to seven transmembrane helices in q = 0.1 isotropic bicelles, ~10 nm diameter isotropic nanodiscs, ~30 nm diameter magnetically aligned macrodiscs, and q = 5 magnetically aligned bicelles are compared.
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Affiliation(s)
- Sang Ho Park
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0307, United States
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36
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Morrissey JH, Tajkhorshid E, Rienstra CM. Nanoscale studies of protein-membrane interactions in blood clotting. J Thromb Haemost 2011; 9 Suppl 1:162-7. [PMID: 21781251 PMCID: PMC3151027 DOI: 10.1111/j.1538-7836.2011.04300.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Most of the steps in the blood clotting cascade require clotting proteins to bind to membrane surfaces with exposed phosphatidylserine. In spite of the importance of these protein-membrane interactions, we still lack a detailed understanding of how clotting proteins interact with membranes and how membranes contribute so profoundly to catalysis. Our laboratories are using multidisciplinary approaches to explore, at atomic-resolution, how blood clotting protein complexes assemble and function on membrane surfaces.
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Affiliation(s)
- J H Morrissey
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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37
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Morgan CR, Hebling CM, Rand KD, Stafford DW, Jorgenson JW, Engen JR. Conformational transitions in the membrane scaffold protein of phospholipid bilayer nanodiscs. Mol Cell Proteomics 2011; 10:M111.010876. [PMID: 21715319 DOI: 10.1074/mcp.m111.010876] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Phospholipid bilayer nanodiscs are model membrane systems that provide an environment where membrane proteins are highly stable and monodisperse without the use of detergents or liposomes. Nanodiscs consist of a discoidal phospholipid bilayer encircled by two copies of an amphipathic alpha helical membrane scaffold protein, which is modeled from apolipoprotein A-1. Hydrogen exchange mass spectrometry was used to probe the structure and dynamics of the scaffold protein in the presence and absence of lipid. On nanodisc self-assembly, the entire scaffold protein gained significant protection from exchange, consistent with a large, protein-wide, structural rearrangement. This protection was short-lived and the scaffold protein was highly deuterated within 2 h. Several regions of the scaffold protein, in both the lipid-free and lipid-associated states, displayed EX1 unfolding kinetics. The rapid deuteration of the scaffold protein and the presence of correlated unfolding events both indicate that nanodiscs are dynamic rather than rigid bodies in solution. This work provides a catalog of the expected scaffold protein peptic peptides in a nanodisc-hydrogen exchange mass spectrometry experiment and their deuterium uptake signatures, data that can be used as a benchmark to verify correct assembly and nanodisc structure. Such reference data will be useful control data for all hydrogen exchange mass spectrometry experiments involving nanodiscs in which transmembrane or lipid-associated proteins are the primary molecule(s) of interest.
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Affiliation(s)
- Christopher R Morgan
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA
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38
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Boettcher JM, Davis-Harrison RL, Clay MC, Nieuwkoop AJ, Ohkubo YZ, Tajkhorshid E, Morrissey JH, Rienstra CM. Atomic view of calcium-induced clustering of phosphatidylserine in mixed lipid bilayers. Biochemistry 2011; 50:2264-73. [PMID: 21294564 PMCID: PMC3069658 DOI: 10.1021/bi1013694] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Membranes play key regulatory roles in biological processes, with bilayer composition exerting marked effects on binding affinities and catalytic activities of a number of membrane-associated proteins. In particular, proteins involved in diverse processes such as vesicle fusion, intracellular signaling cascades, and blood coagulation interact specifically with anionic lipids such as phosphatidylserine (PS) in the presence of Ca(2+) ions. While Ca(2+) is suspected to induce PS clustering in mixed phospholipid bilayers, the detailed structural effects of this ion on anionic lipids are not established. In this study, combining magic angle spinning (MAS) solid-state NMR (SSNMR) measurements of isotopically labeled serine headgroups in mixed lipid bilayers with molecular dynamics (MD) simulations of PS lipid bilayers in the presence of different counterions, we provide site-resolved insights into the effects of Ca(2+) on the structure and dynamics of lipid bilayers. Ca(2+)-induced conformational changes of PS in mixed bilayers are observed in both liposomes and Nanodiscs, a nanoscale membrane mimetic of bilayer patches. Site-resolved multidimensional correlation SSNMR spectra of bilayers containing (13)C,(15)N-labeled PS demonstrate that Ca(2+) ions promote two major PS headgroup conformations, which are well resolved in two-dimensional (13)C-(13)C, (15)N-(13)C, and (31)P-(13)C spectra. The results of MD simulations performed on PS lipid bilayers in the presence or absence of Ca(2+) provide an atomic view of the conformational effects underlying the observed spectra.
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Affiliation(s)
- John M. Boettcher
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | | | - Mary C. Clay
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Andrew J. Nieuwkoop
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Y. Zenmei Ohkubo
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Emad Tajkhorshid
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - James H. Morrissey
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Chad M. Rienstra
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
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39
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Gao T, Blanchette CD, He W, Bourguet F, Ly S, Katzen F, Kudlicki WA, Henderson PT, Laurence TA, Huser T, Coleman MA. Characterizing diffusion dynamics of a membrane protein associated with nanolipoproteins using fluorescence correlation spectroscopy. Protein Sci 2011; 20:437-47. [PMID: 21280134 PMCID: PMC3048428 DOI: 10.1002/pro.577] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 11/29/2010] [Accepted: 12/01/2010] [Indexed: 01/28/2023]
Abstract
Nanolipoprotein particles (NLPs) represent a unique nanometer-sized scaffold for supporting membrane proteins (MP). Characterization of their dynamic shape and association with MP in solution remains a challenge. Here, we present a rapid method of analysis by fluorescence correlation spectroscopy (FCS) to characterize bacteriorhodopsin (bR), a membrane protein capable of forming a NLP complex. By selectively labeling individual components of NLPs during cell-free synthesis, FCS enabled us to measure specific NLP diffusion times and infer size information for different NLP species. The resulting bR-loaded NLPs were shown to be dynamically discoidal in solution with a mean diameter of 7.8 nm. The insertion rate of bR in the complex was ∼55% based on a fit model incorporating two separate diffusion properties to best approximate the FCS data. More importantly, based on these data, we infer that membrane protein associated NLPs are thermodynamically constrained as discs in solution, while empty NLPs appear to be less constrained and dynamically spherical.
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Affiliation(s)
- Tingjuan Gao
- NSF Center for Biophotonics Science and Technology, School of Medicine, University of California DavisSacramento, California 95817
| | - Craig D Blanchette
- Lawrence Livermore National Laboratory, Physics and Life SciencesLivermore, California 94550
| | - Wei He
- NSF Center for Biophotonics Science and Technology, School of Medicine, University of California DavisSacramento, California 95817
| | - Feliza Bourguet
- Lawrence Livermore National Laboratory, Physics and Life SciencesLivermore, California 94550
| | - Sonny Ly
- NSF Center for Biophotonics Science and Technology, School of Medicine, University of California DavisSacramento, California 95817
| | | | | | - Paul T Henderson
- NSF Center for Biophotonics Science and Technology, School of Medicine, University of California DavisSacramento, California 95817
| | - Ted A Laurence
- Lawrence Livermore National Laboratory, Physics and Life SciencesLivermore, California 94550
| | - Thomas Huser
- NSF Center for Biophotonics Science and Technology, School of Medicine, University of California DavisSacramento, California 95817
| | - Matthew A Coleman
- NSF Center for Biophotonics Science and Technology, School of Medicine, University of California DavisSacramento, California 95817
- Lawrence Livermore National Laboratory, Physics and Life SciencesLivermore, California 94550
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40
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Prieto ED, Garda HA. Membrane insertion topology of the central apolipoprotein A-I region. Fluorescence studies using single tryptophan mutants. Biochemistry 2010; 50:466-79. [PMID: 21141907 DOI: 10.1021/bi1009634] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Apolipoprotein A-I (apoAI) contains several amphipathic α-helices. To carry out its function, it exchanges between lipid-free and different lipidated states as bound to membranes or to lipoprotein complexes of different morphology, size, and composition. When bound to membranes or to spherical lipoprotein surfaces, it is thought that most α-helices arrange with their long axis parallel to the membrane surface. However, we previously found that a central region spanning residues 87-112 is exclusively labeled by photoactivable reagents deeply located into the membrane (Córsico et al. (2001) J. Biol. Chem. 276, 16978-16985). A pair of amphipathic α-helical repeats with a particular charge distribution is predicted in this region. In order to study their insertion topology, three single tryptophan mutants, each one containing the tryptophan residue at a selected position in the hydrophobic face of the central Y-helices (W@93, W@104, and W@108), were used. From the accessibility to quenchers located at different membrane depths, distances from the bilayer center of 13.4, 10.5, and 15.7 Å were estimated for positions 93, 104, and 108, respectively. Reported data also indicate that distances between homologous positions (in particular for W@93 and W@104) are very short in dimers in aqueous solution, but they are larger in membrane-bound dimers. Data indicate that an intermolecular central Y-helix bundle would penetrate the membrane perpendicularly to the membrane surface. Intermolecular helix-helix interactions would occur through the hydrophilic helix faces in the membrane-bound bundle but through the hydrophobic faces in the case of dimers in solution.
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Affiliation(s)
- Eduardo D Prieto
- Instituto de Investigaciones Bioquímicas de La Plata, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de La Plata, Facultad de Ciencias Médicas, Calles 60 y 120, La Plata, Argentina
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41
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Kijac A, Shih AY, Nieuwkoop AJ, Schulten K, Sligar SG, Rienstra CM. Lipid-protein correlations in nanoscale phospholipid bilayers determined by solid-state nuclear magnetic resonance. Biochemistry 2010; 49:9190-8. [PMID: 20804175 PMCID: PMC3136391 DOI: 10.1021/bi1013722] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nanodiscs are examples of discoidal nanoscale lipid-protein particles that have been extremely useful for the biochemical and biophysical characterization of membrane proteins. They are discoidal lipid bilayer fragments encircled and stabilized by two amphipathic helical proteins named membrane scaffolding protein (MSP), ~10 nm in size. Nanodiscs are homogeneous, easily prepared with reproducible success, amenable to preparations with a variety of lipids, and stable over a range of temperatures. Here we present solid-state nuclear magnetic resonance (SSNMR) studies on lyophilized, rehydrated POPC Nanodiscs prepared with uniformly (13)C-, (15)N-labeled MSP1D1 (Δ1-11 truncated MSP). Under these conditions, by SSNMR we directly determine the gel-to-liquid crystal lipid phase transition to be at 3 ± 2 °C. Above this phase transition, the lipid (1)H signals have slow transverse relaxation, enabling filtering experiments as previously demonstrated for lipid vesicles. We incorporate this approach into two- and three-dimensional heteronuclear SSNMR experiments to examine the MSP1D1 residues interfacing with the lipid bilayer. These (1)H-(13)C and (1)H-(13)C-(13)C correlation spectra are used to identify and quantify the number of lipid-correlated and solvent-exposed residues by amino acid type, which furthermore is compared with molecular dynamics studies of MSP1D1 in Nanodiscs. This study demonstrates the utility of SSNMR experiments with Nanodiscs for examining lipid-protein interfaces and has important applications for future structural studies of membrane proteins in physiologically relevant formulations.
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Affiliation(s)
- Aleksandra Kijac
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Amy Y. Shih
- Beckman Institute for Advanced Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Andrew J. Nieuwkoop
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Klaus Schulten
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Beckman Institute for Advanced Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Stephen G. Sligar
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Beckman Institute for Advanced Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Chad M. Rienstra
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Beckman Institute for Advanced Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
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42
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Skar-Gislinge N, Simonsen JB, Mortensen K, Feidenhans’l R, Sligar SG, Møller BL, Bjørnholm T, Arleth L. Elliptical structure of phospholipid bilayer nanodiscs encapsulated by scaffold proteins: casting the roles of the lipids and the protein. J Am Chem Soc 2010; 132:13713-22. [PMID: 20828154 PMCID: PMC4120756 DOI: 10.1021/ja1030613] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Phospholipid bilayers host and support the function of membrane proteins and may be stabilized in disc-like nanostructures, allowing for unprecedented solution studies of the assembly, structure, and function of membrane proteins (Bayburt et al. Nano Lett. 2002, 2, 853-856). Based on small-angle neutron scattering in combination with variable-temperature studies of synchrotron small-angle X-ray scattering on nanodiscs in solution, we show that the fundamental nanodisc unit, consisting of a lipid bilayer surrounded by amphiphilic scaffold proteins, possesses intrinsically an elliptical shape. The temperature dependence of the curvature of the nanodiscs prepared with two different phospholipid types (DLPC and POPC) shows that it is the scaffold protein that determines the overall elliptical shape and that the nanodiscs become more circular with increasing temperature. Our data also show that the hydrophobic bilayer thickness is, to a large extent, dictated by the scaffolding protein and adjusted to minimize the hydrophobic mismatch between protein and phospholipid. Our conclusions result from a new comprehensive and molecular-based model of the nanodisc structure and the use of this to analyze the experimental scattering profile from nanodiscs. The model paves the way for future detailed structural studies of functional membrane proteins encapsulated in nanodiscs.
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43
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Hebling CM, Morgan CR, Stafford DW, Jorgenson JW, Rand KD, Engen JR. Conformational analysis of membrane proteins in phospholipid bilayer nanodiscs by hydrogen exchange mass spectrometry. Anal Chem 2010; 82:5415-9. [PMID: 20518534 DOI: 10.1021/ac100962c] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The study of membrane protein structure and enzymology has traditionally been hampered by the inherent insolubility of membrane proteins in aqueous environments and experimental challenges in emulating an in vivo lipid environment. Phospholipid bilayer nanodiscs have recently been shown to be of great use for the study of membrane proteins since they offer a controllable, stable, and monodisperse model membrane with a nativelike lipid bilayer. Here we report the integration of nanodiscs with hydrogen exchange (HX) mass spectrometry (MS) experiments, thereby allowing for analysis of the native conformation of membrane proteins. gamma-Glutamyl carboxylase (GGCX), an approximately 94 kDa transmembrane protein, was inserted into nanodiscs and labeled with deuterium oxide under native conditions. Analytical parameters including sample-handling and chromatographic separation were optimized to measure the incorporation of deuterium into GGCX. Coupling nanodisc technology with HX MS offers an effective approach for investigating the conformation and dynamics of membrane proteins in their native environment and is therefore capable of providing much needed insight into the function of membrane proteins.
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Affiliation(s)
- Christine M Hebling
- Department of Chemistry, Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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44
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Goncalves JA, Ahuja S, Erfani S, Eilers M, Smith SO. Structure and function of G protein-coupled receptors using NMR spectroscopy. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2010; 57:159-80. [PMID: 20633362 PMCID: PMC2907352 DOI: 10.1016/j.pnmrs.2010.04.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Accepted: 04/08/2010] [Indexed: 05/15/2023]
Affiliation(s)
- Joseph A Goncalves
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, NY 11794-5215, USA
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45
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Popot JL. Amphipols, Nanodiscs, and Fluorinated Surfactants: Three Nonconventional Approaches to Studying Membrane Proteins in Aqueous Solutions. Annu Rev Biochem 2010; 79:737-75. [DOI: 10.1146/annurev.biochem.052208.114057] [Citation(s) in RCA: 241] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jean-Luc Popot
- Laboratoire de Physico-Chimie Moléculaire des Protéines Membranaires, Unité Mixte de Recherche 7099, Centre National de la Recherche Scientifique and Université Paris-7 Denis Diderot, Institut de Biologie Physico-Chimique, F-75005 Paris, France; e-mail:
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46
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Morrissey JH, Davis-Harrison RL, Tavoosi N, Ke K, Pureza V, Boettcher JM, Clay MC, Rienstra CM, Ohkubo YZ, Pogorelov TV, Tajkhorshid E. Protein-phospholipid interactions in blood clotting. Thromb Res 2010; 125 Suppl 1:S23-5. [PMID: 20129649 DOI: 10.1016/j.thromres.2010.01.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Most steps of the blood clotting cascade require the assembly of a serine protease with its specific regulatory protein on a suitable phospholipid bilayer. Unfortunately, the molecular details of how blood clotting proteins bind to membrane surfaces remain poorly understood, owing to a dearth of techniques for studying protein-membrane interactions at high resolution. Our laboratories are tackling this question using a combination of approaches, including nanoscale membrane bilayers, solid-state NMR, and large-scale molecular dynamics simulations. These studies are now providing structural insights at atomic resolution into clotting protein-membrane interactions.
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Affiliation(s)
- James H Morrissey
- Department of Biochemistry, College of Medicine, University of Illinois at Urbana-Champaign, 506 S. Mathews Ave., Urbana, IL, USA.
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47
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Bayburt TH, Sligar SG. Membrane protein assembly into Nanodiscs. FEBS Lett 2009; 584:1721-7. [PMID: 19836392 DOI: 10.1016/j.febslet.2009.10.024] [Citation(s) in RCA: 557] [Impact Index Per Article: 37.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Accepted: 10/09/2009] [Indexed: 01/25/2023]
Abstract
Nanodiscs are soluble nanoscale phospholipid bilayers which can self-assemble integral membrane proteins for biophysical, enzymatic or structural investigations. This means for rendering membrane proteins soluble at the single molecule level offers advantages over liposomes or detergent micelles in terms of size, stability, ability to add genetically modifiable features to the Nanodisc structure and ready access to both sides of the phospholipid bilayer domain. Thus the Nanodisc system provides a novel platform for understanding membrane protein function. We provide an overview of the Nanodisc approach and document through several examples many of the applications to the study of the structure and function of integral membrane proteins.
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Affiliation(s)
- Timothy H Bayburt
- Department of Biochemistry, School of Molecular and Cellular Biology, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA
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48
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Katzen F, Peterson TC, Kudlicki W. Membrane protein expression: no cells required. Trends Biotechnol 2009; 27:455-60. [PMID: 19616329 DOI: 10.1016/j.tibtech.2009.05.005] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 05/02/2009] [Accepted: 05/06/2009] [Indexed: 01/10/2023]
Abstract
Structural and functional studies of membrane proteins have been severely hampered by difficulties in producing sufficient quantities of properly folded protein products. It is well established that cell-based expression of membrane proteins is generally problematic and frequently results in low yield, cell toxicity, protein aggregation and misfolding. Owing to its inherent open nature, cell-free protein expression has become a highly promising tool for the fast and efficient production of these difficult-to-express proteins. Here we review the most recent advances in this field, underscoring the potentials and weaknesses of the newly developed approaches and place specific emphasis on the use of nanolipoprotein particles (NLPs or nanodiscs).
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Affiliation(s)
- Federico Katzen
- Life Technologies, 5791 Van Allen Way, Carlsbad, CA 92008, USA
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49
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Characterization and purification of polydisperse reconstituted lipoproteins and nanolipoprotein particles. Int J Mol Sci 2009; 10:2958-2971. [PMID: 19742178 PMCID: PMC2738905 DOI: 10.3390/ijms10072958] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Accepted: 06/22/2009] [Indexed: 01/29/2023] Open
Abstract
Heterogeneity is a fact that plagues the characterization and application of many self-assembled biological constructs. The importance of obtaining particle homogeneity in biological assemblies is a critical goal, as bulk analysis tools often require identical species for reliable interpretation of the results—indeed, important tools of analysis such as x-ray diffraction typically require over 90% purity for effectiveness. This issue bears particular importance in the case of lipoproteins. Lipid-binding proteins known as apolipoproteins can self assemble with liposomes to form reconstituted high density lipoproteins (rHDLs) or nanolipoprotein particles (NLPs) when used for biotechnology applications such as the solubilization of membrane proteins. Typically, the apolipoprotein and phospholipids reactants are self assembled and even with careful assembly protocols the product often contains heterogeneous particles. In fact, size polydispersity in rHDLs and NLPs published in the literature are frequently observed, which may confound the accurate use of analytical methods. In this article, we demonstrate a procedure for producing a pure, monodisperse NLP subpopulation from a polydisperse self-assembly using size exclusion chromatography (SEC) coupled with high resolution particle imaging by atomic force microscopy (AFM). In addition, NLPs have been shown to self assemble both in the presence and absence of detergents such as cholate, yet the effects of cholate on NLP polydispersity and separation has not been systematically examined. Therefore, we examined the separation properties of NLPs assembled in both the absence and presence of cholate using SEC and native gel electrophoresis. From this analysis, NLPs prepared with and without cholate showed particles with well defined diameters spanning a similar size range. However, cholate was shown to have a dramatic affect on NLP separation by SEC and native gel electrophoresis. Furthermore, under conditions where different sized NLPs were not sufficiently separated or purified by SEC, AFM was used to deconvolute the elution pattern of different sized NLPs. From this analysis we were able to purify an NLP subpopulation to 90% size homogeneity by taking extremely fine elutions from the SEC. With this purity, we generate high quality NLP crystals that were over 100 μm in size with little precipitate, which could not be obtained utilizing the traditional size exclusion techniques. This purification procedure and the methods for validation are broadly applicable to other lipoprotein particles.
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Morrissey JH, Pureza V, Davis-Harrison RL, Sligar SG, Rienstra CM, Kijac AZ, Ohkubo YZ, Tajkhorshid E. Protein-membrane interactions: blood clotting on nanoscale bilayers. J Thromb Haemost 2009; 7 Suppl 1:169-72. [PMID: 19630793 PMCID: PMC2839880 DOI: 10.1111/j.1538-7836.2009.03390.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The clotting cascade requires the assembly of protease-cofactor complexes on membranes with exposed anionic phospholipids. Despite their importance, protein-membrane interactions in clotting remain relatively poorly understood. Calcium ions are known to induce anionic phospholipids to cluster, and we propose that clotting proteins assemble preferentially on such anionic lipid-rich microdomains. Until recently, there was no way to control the partitioning of clotting proteins into or out of specific membrane microdomains, so experimenters only knew the average contributions of phospholipids to blood clotting. The development of nanoscale membrane bilayers (Nanodiscs) has now allowed us to probe, with nanometer resolution, how local variations in phospholipid composition regulate the activity of key protease-cofactor complexes in blood clotting. Furthermore, exciting new progress in solid-state NMR and large-scale molecular dynamics simulations allow structural insights into interactions between proteins and membrane surfaces with atomic resolution.
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Affiliation(s)
- J H Morrissey
- Department of Biochemistry, College of Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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