1
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Mitchell-White JI, Briggs DA, Mistry SJ, Mbiwan HA, Kellam B, Holliday ND, Briddon SJ, Kerr ID. A time-resolved Förster resonance energy transfer assay to investigate drug and inhibitor binding to ABCG2. Arch Biochem Biophys 2024; 753:109915. [PMID: 38307314 DOI: 10.1016/j.abb.2024.109915] [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: 10/27/2023] [Revised: 12/21/2023] [Accepted: 01/17/2024] [Indexed: 02/04/2024]
Abstract
The human ATP-binding cassette (ABC) transporter, ABCG2, is responsible for multidrug resistance in some tumours. Detailed knowledge of its activity is crucial for understanding drug transport and resistance in cancer, and has implications for wider pharmacokinetics. The binding of substrates and inhibitors is a key stage in the transport cycle of ABCG2. Here, we describe a novel binding assay using a high affinity fluorescent inhibitor based on Ko143 and time-resolved Förster resonance energy transfer (TR-FRET) to measure saturation binding to ABCG2. This binding is displaced by Ko143 and other known ABCG2 ligands, and is sensitive to the addition of AMP-PNP, a non-hydrolysable ATP analogue. This assay complements the arsenal of methods for determining drug:ABCG2 interactions and has the possibility of being adaptable for other multidrug pumps.
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Affiliation(s)
- James I Mitchell-White
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, The Midlands, UK.
| | - Deborah A Briggs
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Sarah J Mistry
- School of Pharmacy, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Hannah A Mbiwan
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK; School of Pharmacy, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Barrie Kellam
- School of Pharmacy, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Nicholas D Holliday
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Stephen J Briddon
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, The Midlands, UK
| | - Ian D Kerr
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
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2
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Bag S, Bhowmik S. Fluorescence Spectroscopy: A Useful Method to Explore the Interactions of Small Molecule Ligands with DNA Structures. Methods Mol Biol 2024; 2719:33-49. [PMID: 37803111 DOI: 10.1007/978-1-0716-3461-5_3] [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] [Indexed: 10/08/2023]
Abstract
Small molecule ligands-DNA interactions have recently received a lot of attention in the fields of life sciences, medicine, and chemical sciences. To decode these interactions, many strategies have been developed. DNA is the primary target for a wide range of drugs that may interact with DNA in particular or non-specific ways and impact its activities. Fluorescence spectroscopy is a highly advanced and non-invasive technology for measuring the concentrations of substrates and products or identifying characteristic processing states. Small molecule ligands-DNA interaction studies are beneficial not only in comprehending the method of interaction, but also in synthesizing DNA-targeted particular drugs. Several small compounds that bind to DNA are clinically established therapeutic medicines, while their specific mechanism of action is unknown. Figuring out their molecular recognizing patterns is the only way to construct innovative compounds that can target specific DNA sequences with strong affinities. This book chapter will mostly explore several fluorescence spectroscopic methodologies used to investigate interactions between small molecule ligands and DNA. In addition, we provide many approaches for determining a drug's binding mode with DNA. These strategies produce data that is both trustworthy and easy to comprehend. All of the knowledge gained by studying these fluorescence spectroscopies are supposed to lead to the development of more efficient new pharmaceuticals that might aid in the treatment of diseases.
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Affiliation(s)
- Sagar Bag
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, Kolkata, West Bengal, India
| | - Sudipta Bhowmik
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, Kolkata, West Bengal, India.
- Mahatma Gandhi Medical Advanced Research Institute (MGMARI), Sri Balaji Vidyapeeth (Deemed to be University), Pondicherry, India.
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3
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Clark JC, Watson SP, Owen DM. Validation of agent-based models of surface receptor oligomerisation. Trends Pharmacol Sci 2023; 44:643-646. [PMID: 37507263 DOI: 10.1016/j.tips.2023.07.002] [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: 06/05/2023] [Revised: 07/07/2023] [Accepted: 07/07/2023] [Indexed: 07/30/2023]
Abstract
Receptor dimerisation and higher order oligomerisation regulates signalling by a wide variety of transmembrane receptors. We discuss how agent-based modelling (ABM) combined with advanced microscopy and structural studies can provide new insights into the regulation of clustering, including spatial considerations, revealing novel targets for therapeutic intervention.
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Affiliation(s)
- Joanne C Clark
- Institute of Cardiovascular Sciences, Level 1 IBR, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; Centre of Membrane Proteins and Receptors (COMPARE), The Universities of Birmingham and Nottingham, The Midlands, UK.
| | - Steve P Watson
- Institute of Cardiovascular Sciences, Level 1 IBR, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; Centre of Membrane Proteins and Receptors (COMPARE), The Universities of Birmingham and Nottingham, The Midlands, UK
| | - Dylan M Owen
- Centre of Membrane Proteins and Receptors (COMPARE), The Universities of Birmingham and Nottingham, The Midlands, UK; Institute of Immunology and Immunotherapy, IBR Building, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
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4
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Özvegy-Laczka C, Ungvári O, Bakos É. Fluorescence-based methods for studying activity and drug-drug interactions of hepatic solute carrier and ATP binding cassette proteins involved in ADME-Tox. Biochem Pharmacol 2023; 209:115448. [PMID: 36758706 DOI: 10.1016/j.bcp.2023.115448] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 01/31/2023] [Accepted: 02/01/2023] [Indexed: 02/11/2023]
Abstract
In humans, approximately 70% of drugs are eliminated through the liver. This process is governed by the concerted action of membrane transporters and metabolic enzymes. Transporters mediating hepatocellular uptake of drugs belong to the SLC (Solute carrier) superfamily of transporters. Drug efflux either toward the portal vein or into the bile is mainly mediated by active transporters of the ABC (ATP Binding Cassette) family. Alteration in the function and/or expression of liver transporters due to mutations, disease conditions, or co-administration of drugs or food components can result in altered pharmacokinetics. On the other hand, drugs or food components interacting with liver transporters may also interfere with liver function (e.g., bile acid homeostasis) and may even cause liver toxicity. Accordingly, certain transporters of the liver should be investigated already at an early stage of drug development. Most frequently radioactive probes are applied in these drug-transporter interaction tests. However, fluorescent probes are cost-effective and sensitive alternatives to radioligands, and are gaining wider application in drug-transporter interaction tests. In our review, we summarize our current understanding about hepatocyte ABC and SLC transporters affected by drug interactions. We provide an update of the available fluorescent and fluorogenic/activable probes applicable in in vitro or in vivo testing of these ABC and SLC transporters, including near-infrared transporter probes especially suitable for in vivo imaging. Furthermore, our review gives a comprehensive overview of the available fluorescence-based methods, not directly relying on the transport of the probe, suitable for the investigation of hepatic ABC or SLC-type drug transporters.
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Affiliation(s)
- Csilla Özvegy-Laczka
- Institute of Enzymology, RCNS, Eötvös Loránd Research Network, H-1117 Budapest, Magyar tudósok krt. 2., Hungary.
| | - Orsolya Ungvári
- Institute of Enzymology, RCNS, Eötvös Loránd Research Network, H-1117 Budapest, Magyar tudósok krt. 2., Hungary; Doctoral School of Biology, Institute of Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Éva Bakos
- Institute of Enzymology, RCNS, Eötvös Loránd Research Network, H-1117 Budapest, Magyar tudósok krt. 2., Hungary
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5
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Gyöngy Z, Mocsár G, Hegedűs É, Stockner T, Ritter Z, Homolya L, Schamberger A, Orbán TI, Remenyik J, Szakacs G, Goda K. Nucleotide binding is the critical regulator of ABCG2 conformational transitions. eLife 2023; 12:83976. [PMID: 36763413 PMCID: PMC9917445 DOI: 10.7554/elife.83976] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 01/27/2023] [Indexed: 02/11/2023] Open
Abstract
ABCG2 is an exporter-type ABC protein that can expel numerous chemically unrelated xeno- and endobiotics from cells. When expressed in tumor cells or tumor stem cells, ABCG2 confers multidrug resistance, contributing to the failure of chemotherapy. Molecular details orchestrating substrate translocation and ATP hydrolysis remain elusive. Here, we present methods to concomitantly investigate substrate and nucleotide binding by ABCG2 in cells. Using the conformation-sensitive antibody 5D3, we show that the switch from the inward-facing (IF) to the outward-facing (OF) conformation of ABCG2 is induced by nucleotide binding. IF-OF transition is facilitated by substrates, and hindered by the inhibitor Ko143. Direct measurements of 5D3 and substrate binding to ABCG2 indicate that the high-to-low affinity switch of the drug binding site coincides with the transition from the IF to the OF conformation. Low substrate binding persists in the post-hydrolysis state, supporting that dissociation of the ATP hydrolysis products is required to reset the high substrate affinity IF conformation of ABCG2.
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Affiliation(s)
- Zsuzsanna Gyöngy
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of DebrecenDebrecenHungary,Doctoral School of Molecular Cell and Immune Biology, University of DebrecenDebrecenHungary
| | - Gábor Mocsár
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of DebrecenDebrecenHungary
| | - Éva Hegedűs
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of DebrecenDebrecenHungary
| | - Thomas Stockner
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of ViennaViennaAustria
| | - Zsuzsanna Ritter
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of DebrecenDebrecenHungary,Doctoral School of Molecular Cell and Immune Biology, University of DebrecenDebrecenHungary
| | - László Homolya
- Institute of Enzymology, Research Centre for Natural SciencesBudapestHungary
| | - Anita Schamberger
- Institute of Enzymology, Research Centre for Natural SciencesBudapestHungary
| | - Tamás I Orbán
- Institute of Enzymology, Research Centre for Natural SciencesBudapestHungary
| | - Judit Remenyik
- Institute of Food Technology, Faculty of Agricultural and Food Sciences and Environmental Management, University of DebrecenDebrecenHungary
| | - Gergely Szakacs
- Institute of Enzymology, Research Centre for Natural SciencesBudapestHungary,Institute of Cancer Research, Medical University of ViennaViennaAustria
| | - Katalin Goda
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of DebrecenDebrecenHungary
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6
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Krishnarjuna B, Ramamoorthy A. Detergent-Free Isolation of Membrane Proteins and Strategies to Study Them in a Near-Native Membrane Environment. Biomolecules 2022; 12:1076. [PMID: 36008970 PMCID: PMC9406181 DOI: 10.3390/biom12081076] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 07/31/2022] [Accepted: 08/02/2022] [Indexed: 02/06/2023] Open
Abstract
Atomic-resolution structural studies of membrane-associated proteins and peptides in a membrane environment are important to fully understand their biological function and the roles played by them in the pathology of many diseases. However, the complexity of the cell membrane has severely limited the application of commonly used biophysical and biochemical techniques. Recent advancements in NMR spectroscopy and cryoEM approaches and the development of novel membrane mimetics have overcome some of the major challenges in this area. For example, the development of a variety of lipid-nanodiscs has enabled stable reconstitution and structural and functional studies of membrane proteins. In particular, the ability of synthetic amphipathic polymers to isolate membrane proteins directly from the cell membrane, along with the associated membrane components such as lipids, without the use of a detergent, has opened new avenues to study the structure and function of membrane proteins using a variety of biophysical and biological approaches. This review article is focused on covering the various polymers and approaches developed and their applications for the functional reconstitution and structural investigation of membrane proteins. The unique advantages and limitations of the use of synthetic polymers are also discussed.
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Affiliation(s)
- Bankala Krishnarjuna
- Department of Chemistry and Biophysics, Biomedical Engineering, Macromolecular Science and Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Ayyalusamy Ramamoorthy
- Department of Chemistry and Biophysics, Biomedical Engineering, Macromolecular Science and Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, MI 48109-1055, USA
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7
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Stoddart LA, Goulding J, Briddon SJ. Advances in the application of fluorescence correlation spectroscopy to study detergent purified and encapsulated membrane proteins. Int J Biochem Cell Biol 2022; 146:106210. [PMID: 35390493 DOI: 10.1016/j.biocel.2022.106210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 03/30/2022] [Accepted: 04/01/2022] [Indexed: 11/25/2022]
Abstract
Fluorescence correlation spectroscopy (FCS) is a quantitative spectroscopy technique which could potentially increase throughput and sensitivity of screening for ligand, substrate and inhibitor binding to membrane proteins in solution. However, the purification of membrane proteins in their active forms is complex, as the lipid bilayer provides stability and its removal often causes the protein to become conformationally unstable. This has limited the application of biophysical techniques such as FCS to study the function of membrane proteins. The recent application of native extraction techniques such as styrene maleic acid lipid particles (SMALPs) has resolved this issue and FCS has emerged as a powerful option for studying proteins extracted in this way. This review will discuss the application of FCS to study purified membrane proteins in detergent micelles, nanodiscs and SMALPs and its potential to be used routinely in membrane protein drug discovery.
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Affiliation(s)
- Leigh A Stoddart
- Cell Signalling and Pharmacology Research Group, Division of Physiology Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, NG7 2UH, UK; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, The Midlands, UK
| | - Joëlle Goulding
- Cell Signalling and Pharmacology Research Group, Division of Physiology Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, NG7 2UH, UK; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, The Midlands, UK
| | - Stephen J Briddon
- Cell Signalling and Pharmacology Research Group, Division of Physiology Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, NG7 2UH, UK; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, The Midlands, UK.
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8
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Laurence MJ, Carpenter TS, Laurence TA, Coleman MA, Shelby M, Liu C. Biophysical Characterization of Membrane Proteins Embedded in Nanodiscs Using Fluorescence Correlation Spectroscopy. MEMBRANES 2022; 12:membranes12040392. [PMID: 35448362 PMCID: PMC9028781 DOI: 10.3390/membranes12040392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 03/29/2022] [Accepted: 03/30/2022] [Indexed: 02/04/2023]
Abstract
Proteins embedded in biological membranes perform essential functions in all organisms, serving as receptors, transporters, channels, cell adhesion molecules, and other supporting cellular roles. These membrane proteins comprise ~30% of all human proteins and are the targets of ~60% of FDA-approved drugs, yet their extensive characterization using established biochemical and biophysical methods has continued to be elusive due to challenges associated with the purification of these insoluble proteins. In response, the development of nanodisc techniques, such as nanolipoprotein particles (NLPs) and styrene maleic acid polymers (SMALPs), allowed membrane proteins to be expressed and isolated in solution as part of lipid bilayer rafts with defined, consistent nanometer sizes and compositions, thus enabling solution-based measurements. Fluorescence correlation spectroscopy (FCS) is a relatively simple yet powerful optical microscopy-based technique that yields quantitative biophysical information, such as diffusion kinetics and concentrations, about individual or interacting species in solution. Here, we first summarize current nanodisc techniques and FCS fundamentals. We then provide a focused review of studies that employed FCS in combination with nanodisc technology to investigate a handful of membrane proteins, including bacteriorhodopsin, bacterial division protein ZipA, bacterial membrane insertases SecYEG and YidC, Yersinia pestis type III secretion protein YopB, yeast cell wall stress sensor Wsc1, epidermal growth factor receptor (EGFR), ABC transporters, and several G protein-coupled receptors (GPCRs).
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Affiliation(s)
- Matthew J. Laurence
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; (M.J.L.); (T.S.C.); (M.A.C.)
| | - Timothy S. Carpenter
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; (M.J.L.); (T.S.C.); (M.A.C.)
| | - Ted A. Laurence
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA;
| | - Matthew A. Coleman
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; (M.J.L.); (T.S.C.); (M.A.C.)
- Department of Radiation Oncology, University of California Davis, Sacramento, CA 95616, USA
| | - Megan Shelby
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; (M.J.L.); (T.S.C.); (M.A.C.)
- Correspondence: (M.S.); (C.L.)
| | - Chao Liu
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; (M.J.L.); (T.S.C.); (M.A.C.)
- Correspondence: (M.S.); (C.L.)
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9
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Orekhov PS, Bozdaganyan ME, Voskoboynikova N, Mulkidjanian AY, Karlova MG, Yudenko A, Remeeva A, Ryzhykau YL, Gushchin I, Gordeliy VI, Sokolova OS, Steinhoff HJ, Kirpichnikov MP, Shaitan KV. Mechanisms of Formation, Structure, and Dynamics of Lipoprotein Discs Stabilized by Amphiphilic Copolymers: A Comprehensive Review. NANOMATERIALS 2022; 12:nano12030361. [PMID: 35159706 PMCID: PMC8838559 DOI: 10.3390/nano12030361] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 01/15/2022] [Accepted: 01/20/2022] [Indexed: 12/16/2022]
Abstract
Amphiphilic copolymers consisting of alternating hydrophilic and hydrophobic units account for a major recent methodical breakthrough in the investigations of membrane proteins. Styrene–maleic acid (SMA), diisobutylene–maleic acid (DIBMA), and related copolymers have been shown to extract membrane proteins directly from lipid membranes without the need for classical detergents. Within the particular experimental setup, they form disc-shaped nanoparticles with a narrow size distribution, which serve as a suitable platform for diverse kinds of spectroscopy and other biophysical techniques that require relatively small, homogeneous, water-soluble particles of separate membrane proteins in their native lipid environment. In recent years, copolymer-encased nanolipoparticles have been proven as suitable protein carriers for various structural biology applications, including cryo-electron microscopy (cryo-EM), small-angle scattering, and conventional and single-molecule X-ray diffraction experiments. Here, we review the current understanding of how such nanolipoparticles are formed and organized at the molecular level with an emphasis on their chemical diversity and factors affecting their size and solubilization efficiency.
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Affiliation(s)
- Philipp S. Orekhov
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (M.E.B.); (M.G.K.); (O.S.S.); (M.P.K.)
- Faculty of Biology, Shenzhen MSU-BIT University, Shenzhen 518172, China
- Institute of Personalized Medicine, Sechenov University, 119146 Moscow, Russia
- Correspondence: (P.S.O.); (K.V.S.)
| | - Marine E. Bozdaganyan
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (M.E.B.); (M.G.K.); (O.S.S.); (M.P.K.)
- Faculty of Biology, Shenzhen MSU-BIT University, Shenzhen 518172, China
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Natalia Voskoboynikova
- Department of Physics, University of Osnabrück, Barbarastrasse 7, 49076 Osnabrück, Germany; (N.V.); (A.Y.M.); (H.-J.S.)
| | - Armen Y. Mulkidjanian
- Department of Physics, University of Osnabrück, Barbarastrasse 7, 49076 Osnabrück, Germany; (N.V.); (A.Y.M.); (H.-J.S.)
- Faculty of Bioengineering and Bioinformatics and Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Maria G. Karlova
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (M.E.B.); (M.G.K.); (O.S.S.); (M.P.K.)
| | - Anna Yudenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia; (A.Y.); (A.R.); (Y.L.R.); (I.G.); (V.I.G.)
| | - Alina Remeeva
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia; (A.Y.); (A.R.); (Y.L.R.); (I.G.); (V.I.G.)
| | - Yury L. Ryzhykau
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia; (A.Y.); (A.R.); (Y.L.R.); (I.G.); (V.I.G.)
| | - Ivan Gushchin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia; (A.Y.); (A.R.); (Y.L.R.); (I.G.); (V.I.G.)
| | - Valentin I. Gordeliy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia; (A.Y.); (A.R.); (Y.L.R.); (I.G.); (V.I.G.)
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, 52428 Jülich, Germany
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-CEA-CNRS, 38000 Grenoble, France
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Olga S. Sokolova
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (M.E.B.); (M.G.K.); (O.S.S.); (M.P.K.)
- Faculty of Biology, Shenzhen MSU-BIT University, Shenzhen 518172, China
| | - Heinz-Jürgen Steinhoff
- Department of Physics, University of Osnabrück, Barbarastrasse 7, 49076 Osnabrück, Germany; (N.V.); (A.Y.M.); (H.-J.S.)
| | - Mikhail P. Kirpichnikov
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (M.E.B.); (M.G.K.); (O.S.S.); (M.P.K.)
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
| | - Konstantin V. Shaitan
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (M.E.B.); (M.G.K.); (O.S.S.); (M.P.K.)
- Correspondence: (P.S.O.); (K.V.S.)
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10
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Broadbent L, Depping P, Lodé A, Vaitsopoulou A, Hardy D, Ayub H, Mitchell-White J, Kerr ID, Goddard AD, Bill RM, Rothnie AJ. Detergent-Free Membrane Protein Purification Using SMA Polymer. Methods Mol Biol 2022; 2507:389-404. [PMID: 35773594 DOI: 10.1007/978-1-0716-2368-8_21] [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] [Indexed: 06/15/2023]
Abstract
One of the big challenges for the study of structure and function of membrane proteins is the need to extract them from the membrane. Traditionally this was achieved using detergents which disrupt the membrane and form a micelle around the protein, but this can cause issues with protein function and/or stability. In 2009 an alternative approach was reported, using styrene maleic acid (SMA) copolymer to extract small discs of lipid bilayer encapsulated by the polymer and termed SMALPs (SMA lipid particles). Since then this approach has been shown to work for a range of different proteins from many different expression systems. It allows the extraction and purification of a target protein while maintaining a lipid bilayer environment. Recently this has led to several new high-resolution structures and novel insights to function. As with any method there are some limitations and issues to be aware of. Here we describe a standard protocol for preparation of the polymer and its use for membrane protein purification, and also include details of typical challenges that may be encountered and possible ways to address those.
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Affiliation(s)
- Luke Broadbent
- College of Health & Life Sciences, Aston University, Birmingham, UK
| | - Peer Depping
- College of Health & Life Sciences, Aston University, Birmingham, UK
| | - Alexis Lodé
- College of Health & Life Sciences, Aston University, Birmingham, UK
| | | | - David Hardy
- College of Health & Life Sciences, Aston University, Birmingham, UK
- School of Biosciences, University of Birmingham, Birmingham, UK
| | - Hoor Ayub
- College of Health & Life Sciences, Aston University, Birmingham, UK
- Faculty of Health & Life Sciences, Coventry University, Coventry, UK
| | - James Mitchell-White
- School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - Ian D Kerr
- School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK
| | - Alan D Goddard
- College of Health & Life Sciences, Aston University, Birmingham, UK
| | - Roslyn M Bill
- College of Health & Life Sciences, Aston University, Birmingham, UK
| | - Alice J Rothnie
- College of Health & Life Sciences, Aston University, Birmingham, UK.
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11
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Hawkins OP, Jahromi CPT, Gulamhussein AA, Nestorow S, Bahra T, Shelton C, Owusu-Mensah QK, Mohiddin N, O'Rourke H, Ajmal M, Byrnes K, Khan M, Nahar NN, Lim A, Harris C, Healy H, Hasan SW, Ahmed A, Evans L, Vaitsopoulou A, Akram A, Williams C, Binding J, Thandi RK, Joby A, Guest A, Tariq MZ, Rasool F, Cavanagh L, Kang S, Asparuhov B, Jestin A, Dafforn TR, Simms J, Bill RM, Goddard AD, Rothnie AJ. Membrane protein extraction and purification using partially-esterified SMA polymers. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2021; 1863:183758. [PMID: 34480878 PMCID: PMC8484863 DOI: 10.1016/j.bbamem.2021.183758] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/16/2021] [Accepted: 08/24/2021] [Indexed: 12/15/2022]
Abstract
Styrene maleic acid (SMA) polymers have proven to be very successful for the extraction of membrane proteins, forming SMA lipid particles (SMALPs), which maintain a lipid bilayer around the membrane protein. SMALP-encapsulated membrane proteins can be used for functional and structural studies. The SMALP approach allows retention of important protein-annular lipid interactions, exerts lateral pressure, and offers greater stability than traditional detergent solubilisation. However, SMA polymer does have some limitations, including a sensitivity to divalent cations and low pH, an absorbance spectrum that overlaps with many proteins, and possible restrictions on protein conformational change. Various modified polymers have been developed to try to overcome these challenges, but no clear solution has been found. A series of partially-esterified variants of SMA (SMA 2625, SMA 1440 and SMA 17352) has previously been shown to be highly effective for solubilisation of plant and cyanobacterial thylakoid membranes. It was hypothesised that the partial esterification of maleic acid groups would increase tolerance to divalent cations. Therefore, these partially-esterified polymers were tested for the solubilisation of lipids and membrane proteins, and their tolerance to magnesium ions. It was found that all partially esterified polymers were capable of solubilising and purifying a range of membrane proteins, but the yield of protein was lower with SMA 1440, and the degree of purity was lower for both SMA 1440 and SMA 17352. SMA 2625 performed comparably to SMA 2000. SMA 1440 also showed an increased sensitivity to divalent cations. Thus, it appears the interactions between SMA and divalent cations are more complex than proposed and require further investigation.
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Affiliation(s)
- Olivia P Hawkins
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | | | - Aiman A Gulamhussein
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Stephanie Nestorow
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Taranpreet Bahra
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Christian Shelton
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Quincy K Owusu-Mensah
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Naadiya Mohiddin
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Hannah O'Rourke
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Mariam Ajmal
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Kara Byrnes
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Madiha Khan
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Nila N Nahar
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Arcella Lim
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Cassandra Harris
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Hannah Healy
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Syeda W Hasan
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Asma Ahmed
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Lora Evans
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Afroditi Vaitsopoulou
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Aneel Akram
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Chris Williams
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Johanna Binding
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Rumandeep K Thandi
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Aswathy Joby
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Ashley Guest
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Mohammad Z Tariq
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Farah Rasool
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Luke Cavanagh
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Simran Kang
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Biser Asparuhov
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Aleksandr Jestin
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Timothy R Dafforn
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - John Simms
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Roslyn M Bill
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Alan D Goddard
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Alice J Rothnie
- College of Health & Life Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK.
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12
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Biophysical characterisation of SMALPs. Biochem Soc Trans 2021; 49:2037-2050. [PMID: 34643233 DOI: 10.1042/bst20201088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/22/2021] [Accepted: 09/23/2021] [Indexed: 11/17/2022]
Abstract
Membrane proteins such as receptors, ion channels and transport proteins are important drug targets. The structure-based study of membrane proteins is challenging, especially when the target protein contains both soluble and insoluble domains. Most membrane proteins are insoluble in aqueous solvent and embedded in the plasma membrane lipid bilayer, which significantly complicates biophysical studies. Poly(styrene-co-maleic acid) (SMA) and other polymer derivatives are increasingly common solubilisation agents, used to isolate membrane proteins stabilised in their native lipid environment in the total absence of detergent. Since the initial report of SMA-mediated solubilisation, and the formation of SMA lipid particles (SMALPs), this technique can directly isolate therapeutic targets from biological membranes, including G-protein coupled receptors (GPCRs). SMA now allows biophysical and structural analyses of membrane proteins in solution that was not previously possible. Here, we critically review several existing biophysical techniques compatible with SMALPs, with a focus on hydrodynamic analysis, microcalorimetric analysis and optical spectroscopic techniques.
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13
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Zampieri V, Hilpert C, Garnier M, Gestin Y, Delolme S, Martin J, Falson P, Launay G, Chaptal V. The Det.Belt Server: A Tool to Visualize and Estimate Amphipathic Solvent Belts around Membrane Proteins. MEMBRANES 2021; 11:459. [PMID: 34206634 PMCID: PMC8307592 DOI: 10.3390/membranes11070459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/11/2021] [Accepted: 06/17/2021] [Indexed: 11/23/2022]
Abstract
Detergents wrap around membrane proteins to form a belt covering the hydrophobic part of the protein serving for membrane insertion and interaction with lipids. The number of detergent monomers forming this belt is usually unknown to investigators, unless dedicated detergent quantification is undertaken, which for many projects is difficult to setup. Yet, having an approximate knowledge of the amount of detergent forming the belt is extremely useful, to better grasp the protein of interest in interaction with its direct environment rather than picturing the membrane protein "naked". We created the Det.Belt server to dress up membrane proteins and represent in 3D the bulk made by detergent molecules wrapping in a belt. Many detergents are included in a database, allowing investigators to screen in silico the effect of different detergents around their membrane protein. The input number of detergents is changeable with fast recomputation of the belt for interactive usage. Metrics representing the belt are readily available together with scripts to render quality 3D images for publication. The Det.Belt server is a tool for biochemists to better grasp their sample.
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Affiliation(s)
- Veronica Zampieri
- EMBL Grenoble, 71 Avenue des Martyrs, CS 90181, CEDEX 9, 38042 Grenoble, France;
| | - Cécile Hilpert
- Molecular Microbiology and Structural Biochemistry Laboratory (CNRS UMR 5086), University of Lyon, IBCP, 7 Passage du Vercors, 69367 Lyon, France; (C.H.); (M.G.); (Y.G.); (S.D.); (J.M.); (P.F.)
| | - Mélanie Garnier
- Molecular Microbiology and Structural Biochemistry Laboratory (CNRS UMR 5086), University of Lyon, IBCP, 7 Passage du Vercors, 69367 Lyon, France; (C.H.); (M.G.); (Y.G.); (S.D.); (J.M.); (P.F.)
| | - Yannick Gestin
- Molecular Microbiology and Structural Biochemistry Laboratory (CNRS UMR 5086), University of Lyon, IBCP, 7 Passage du Vercors, 69367 Lyon, France; (C.H.); (M.G.); (Y.G.); (S.D.); (J.M.); (P.F.)
| | - Sébastien Delolme
- Molecular Microbiology and Structural Biochemistry Laboratory (CNRS UMR 5086), University of Lyon, IBCP, 7 Passage du Vercors, 69367 Lyon, France; (C.H.); (M.G.); (Y.G.); (S.D.); (J.M.); (P.F.)
| | - Juliette Martin
- Molecular Microbiology and Structural Biochemistry Laboratory (CNRS UMR 5086), University of Lyon, IBCP, 7 Passage du Vercors, 69367 Lyon, France; (C.H.); (M.G.); (Y.G.); (S.D.); (J.M.); (P.F.)
| | - Pierre Falson
- Molecular Microbiology and Structural Biochemistry Laboratory (CNRS UMR 5086), University of Lyon, IBCP, 7 Passage du Vercors, 69367 Lyon, France; (C.H.); (M.G.); (Y.G.); (S.D.); (J.M.); (P.F.)
| | - Guillaume Launay
- Molecular Microbiology and Structural Biochemistry Laboratory (CNRS UMR 5086), University of Lyon, IBCP, 7 Passage du Vercors, 69367 Lyon, France; (C.H.); (M.G.); (Y.G.); (S.D.); (J.M.); (P.F.)
| | - Vincent Chaptal
- Molecular Microbiology and Structural Biochemistry Laboratory (CNRS UMR 5086), University of Lyon, IBCP, 7 Passage du Vercors, 69367 Lyon, France; (C.H.); (M.G.); (Y.G.); (S.D.); (J.M.); (P.F.)
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14
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Biological insights from SMA-extracted proteins. Biochem Soc Trans 2021; 49:1349-1359. [PMID: 34110372 PMCID: PMC8286838 DOI: 10.1042/bst20201067] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/12/2021] [Accepted: 05/17/2021] [Indexed: 02/08/2023]
Abstract
In the twelve years since styrene maleic acid (SMA) was first used to extract and purify a membrane protein within a native lipid bilayer, this technological breakthrough has provided insight into the structural and functional details of protein–lipid interactions. Most recently, advances in cryo-EM have demonstrated that SMA-extracted membrane proteins are a rich-source of structural data. For example, it has been possible to resolve the details of annular lipids and protein–protein interactions within complexes, the nature of lipids within central cavities and binding pockets, regions involved in stabilising multimers, details of terminal residues that would otherwise remain unresolved and the identification of physiologically relevant states. Functionally, SMA extraction has allowed the analysis of membrane proteins that are unstable in detergents, the characterization of an ultrafast component in the kinetics of electron transfer that was not possible in detergent-solubilised samples and quantitative, real-time measurement of binding assays with low concentrations of purified protein. While the use of SMA comes with limitations such as its sensitivity to low pH and divalent cations, its major advantage is maintenance of a protein's lipid bilayer. This has enabled researchers to view and assay proteins in an environment close to their native ones, leading to new structural and mechanistic insights.
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15
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Brown CJ, Trieber C, Overduin M. Structural biology of endogenous membrane protein assemblies in native nanodiscs. Curr Opin Struct Biol 2021; 69:70-77. [PMID: 33915422 DOI: 10.1016/j.sbi.2021.03.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/11/2021] [Accepted: 03/21/2021] [Indexed: 01/17/2023]
Abstract
The advent of amphiphilic copolymers enables integral membrane proteins to be solubilized into stable 10-30 nm native nanodiscs to resolve their multisubunit structures, post-translational modifications, endogenous lipid bilayers, and small molecule ligands. This breakthrough has positioned biological membrane:protein assemblies (memteins) as fundamental functional units of cellular membranes. Herein, we review copolymer design strategies and methods for the characterization of transmembrane proteins within native nanodiscs by cryo-electron microscopy (cryo-EM), transmission electron microscopy, nuclear magnetic resonance spectroscopy, electron paramagnetic resonance, X-ray diffraction, surface plasmon resonance, and mass spectrometry.
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Affiliation(s)
- Chanelle J Brown
- Department of Chemistry and Macromolecules Innovation Institute, Virginia Tech, Blacksburg, USA
| | - Catharine Trieber
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | - Michael Overduin
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada.
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16
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Lemieux MJ, Overduin M. Structure and function of proteins in membranes and nanodiscs. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183445. [PMID: 32841614 PMCID: PMC7443088 DOI: 10.1016/j.bbamem.2020.183445] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The field of membrane structural biology represents a fast-moving field with exciting developments including native nanodiscs that allow preparation of complexes of post-translationally modified proteins bound to biological lipids. This has led to conceptual advances including biological membrane:protein assemblies or “memteins” as the fundamental functional units of biological membranes. Tools including cryo-electron microscopy and X-ray crystallography are maturing such that it is becoming increasingly feasible to solve structures of large, multicomponent complexes, while complementary methods including nuclear magnetic resonance spectroscopy yield unique insights into interactions and dynamics. Challenges remain, including elucidating exactly how lipids and ligands are recognized at atomic resolution and transduce signals across asymmetric bilayers. In this special volume some of the latest thinking and methods are gathered through the analysis of a range of transmembrane targets. Ongoing work on areas including polymer design, protein labelling and microfluidic technologies will ensure continued progress on improving resolution and throughput, providing deeper understanding of this most important group of targets.
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Affiliation(s)
- M Joanne Lemieux
- Department of Biochemistry, Membrane Protein Disease Research Group, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Michael Overduin
- Department of Biochemistry, Membrane Protein Disease Research Group, University of Alberta, Edmonton, AB T6G 2H7, Canada.
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17
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Hothersall JD, Jones AY, Dafforn TR, Perrior T, Chapman KL. Releasing the technical 'shackles' on GPCR drug discovery: opportunities enabled by detergent-free polymer lipid particle (PoLiPa) purification. Drug Discov Today 2020; 25:S1359-6446(20)30337-8. [PMID: 32835806 DOI: 10.1016/j.drudis.2020.08.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 07/04/2020] [Accepted: 08/13/2020] [Indexed: 12/19/2022]
Abstract
G-protein-coupled receptor (GPCR) drug research is presently hindered by the technical challenges associated with generating purified receptors. Consequently, the application of critical modern discovery technologies has been limited, and the vast untapped opportunity for new GPCR-directed medicines is not being realised. A simple but transformative solution is to purify receptors without removing them from their native phospholipid environment by using polymer lipid particle (PoLiPa) technology, with reagents such as styrene-maleic acid co-polymer (SMA). Compared with contemporary detergent-based and stabilising mutagenesis methods, the PoLiPa approach is simple and generic and, therefore, offers huge advantages, with the potential to revolutionise GPCR research by facilitating the availability of the purified receptors that are required for structural biology, biophysical, and panning technologies.
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Affiliation(s)
- J Daniel Hothersall
- Domainex Ltd, Chesterford Research Park, Little Chesterford, Saffron Walden, CB10 1XL, UK.
| | - Andrew Y Jones
- Domainex Ltd, Chesterford Research Park, Little Chesterford, Saffron Walden, CB10 1XL, UK
| | - Tim R Dafforn
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Trevor Perrior
- Domainex Ltd, Chesterford Research Park, Little Chesterford, Saffron Walden, CB10 1XL, UK
| | - Kathryn L Chapman
- Domainex Ltd, Chesterford Research Park, Little Chesterford, Saffron Walden, CB10 1XL, UK
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18
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Grime RL, Goulding J, Uddin R, Stoddart LA, Hill SJ, Poyner DR, Briddon SJ, Wheatley M. Single molecule binding of a ligand to a G-protein-coupled receptor in real time using fluorescence correlation spectroscopy, rendered possible by nano-encapsulation in styrene maleic acid lipid particles. NANOSCALE 2020; 12:11518-11525. [PMID: 32428052 DOI: 10.1039/d0nr01060j] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The fundamental importance of membrane proteins in cellular processes has driven a marked increase in the use of membrane mimetic approaches for studying and exploiting these proteins. Nano-encapsulation strategies which preserve the native lipid bilayer environment are particularly attractive. Consequently, the use of poly(styrene co-maleic acid) (SMA) has been widely adopted to solubilise proteins directly from cell membranes by spontaneously forming "SMA Lipid Particles" (SMALPs). G-protein-coupled receptors (GPCRs) are ubiquitous "chemical switches", are central to cell signalling throughout the evolutionary tree, form the largest family of membrane proteins in humans and are a major drug discovery target. GPCR-SMALPs that retain binding capability would be a versatile platform for a wide range of down-stream applications. Here, using the adenosine A2A receptor (A2AR) as an archetypical GPCR, we show for the first time the utility of fluorescence correlation spectroscopy (FCS) to characterise the binding capability of GPCRs following nano-encapsulation. Unbound fluorescent ligand CA200645 exhibited a monophasic autocorrelation curve (dwell time, τD = 68 ± 2 μs; diffusion coefficient, D = 287 ± 15 μm2 s-1). In the presence of A2AR-SMALP, bound ligand was also evident (τD = 625 ± 23 μs; D = 30 ± 4 μm2 s-1). Using a non-receptor control (ZipA-SMALP) plus competition binding confirmed that this slower component represented binding to the encapsulated A2AR. Consequently, the combination of GPCR-SMALP and FCS is an effective platform for the quantitative real-time characterisation of nano-encapsulated receptors, with single molecule sensitivity, that will have widespread utility for future exploitation of GPCR-SMALPs in general.
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Affiliation(s)
- Rachael L Grime
- School of Biosciences, University of Birmingham, Birmingham, B15 2TT, UK and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Joelle Goulding
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK and Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Romez Uddin
- Life and Health Sciences, Aston University, Birmingham B4 7ET, UK
| | - Leigh A Stoddart
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK and Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Stephen J Hill
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK and Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
| | - David R Poyner
- Life and Health Sciences, Aston University, Birmingham B4 7ET, UK
| | - Stephen J Briddon
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK and Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Mark Wheatley
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK and Centre for Sport, Exercise and Life Sciences, Faculty of Health and Life Sciences, Alison Gingell Building, Coventry University, Coventry, CV1 2DS, UK.
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