1
|
Heller WT. Small-Angle Neutron Scattering for Studying Lipid Bilayer Membranes. Biomolecules 2022; 12:1591. [PMID: 36358941 PMCID: PMC9687511 DOI: 10.3390/biom12111591] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/18/2022] [Accepted: 10/26/2022] [Indexed: 09/23/2023] Open
Abstract
Small-angle neutron scattering (SANS) is a powerful tool for studying biological membranes and model lipid bilayer membranes. The length scales probed by SANS, being from 1 nm to over 100 nm, are well-matched to the relevant length scales of the bilayer, particularly when it is in the form of a vesicle. However, it is the ability of SANS to differentiate between isotopes of hydrogen as well as the availability of deuterium labeled lipids that truly enable SANS to reveal details of membranes that are not accessible with the use of other techniques, such as small-angle X-ray scattering. In this work, an overview of the use of SANS for studying unilamellar lipid bilayer vesicles is presented. The technique is briefly presented, and the power of selective deuteration and contrast variation methods is discussed. Approaches to modeling SANS data from unilamellar lipid bilayer vesicles are presented. Finally, recent examples are discussed. While the emphasis is on studies of unilamellar vesicles, examples of the use of SANS to study intact cells are also presented.
Collapse
Affiliation(s)
- William T Heller
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| |
Collapse
|
2
|
Heterogeneity and deformation behavior of lipid vesicles. Curr Opin Colloid Interface Sci 2022. [DOI: 10.1016/j.cocis.2022.101646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
3
|
Schäfer J, Nehls J, Schön M, Mey I, Steinem C. Leaflet-Dependent Distribution of PtdIns[4,5]P 2 in Supported Model Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:1320-1328. [PMID: 31951413 DOI: 10.1021/acs.langmuir.9b03793] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Supported planar lipid bilayers (SLBs) prepared by spreading of unilamellar vesicles on hydrophilic substrates such as silicon dioxide are frequently used to investigate lipid-protein interactions by means of surface-sensitive methods. In recent years, the receptor lipid phosphatidylinositol-4,5-bisphosphate (PtdIns[4,5]P2) became particularly important as a significant number of proteins bind to this lipid at the inner leaflet of the plasma membrane. Here, we investigated how the lipid PtdIns[4,5]P2 distributes between the two leaflets of an SLB on SiO2 surfaces. We prepared SLBs on SiO2 by spreading small unilamellar vesicles and quantified the adsorption of PtdIns[4,5]P2 binding proteins providing information about the accessibility of PtdIns[4,5]P2. We compared protein binding to PtdIns[4,5]P2 in SLBs with that in lipid monolayers on a 1,1,1-trimethyl-N-(trimethylsilyl)silanamine-functionalized SiO2 surface using reflectometric interference spectroscopy and atomic force microscopy. Our results clearly demonstrate that the accessibility of PtdIns[4,5]P2 for protein binding is reduced in SLBs compared to that in supported hybrid membranes, which is discussed in terms of PtdIns[4,5]P2 distribution in the two leaflets of SLBs.
Collapse
Affiliation(s)
- Jonas Schäfer
- Institute of Organic and Biomolecular Chemistry , University of Göttingen , Tammannstrasse 2 , 37077 Göttingen , Germany
| | - Jessica Nehls
- Institute of Organic and Biomolecular Chemistry , University of Göttingen , Tammannstrasse 2 , 37077 Göttingen , Germany
| | - Markus Schön
- Institute of Organic and Biomolecular Chemistry , University of Göttingen , Tammannstrasse 2 , 37077 Göttingen , Germany
| | - Ingo Mey
- Institute of Organic and Biomolecular Chemistry , University of Göttingen , Tammannstrasse 2 , 37077 Göttingen , Germany
| | - Claudia Steinem
- Institute of Organic and Biomolecular Chemistry , University of Göttingen , Tammannstrasse 2 , 37077 Göttingen , Germany
- Max Planck Institute for Dynamics and Self-Organization , Am Fassberg 17 , 37077 Göttingen , Germany
| |
Collapse
|
4
|
Agrawal A, Ramachandran R. Exploring the links between lipid geometry and mitochondrial fission: Emerging concepts. Mitochondrion 2019; 49:305-313. [DOI: 10.1016/j.mito.2019.07.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/22/2019] [Accepted: 07/24/2019] [Indexed: 01/08/2023]
|
5
|
Irajizad E, Ramachandran R, Agrawal A. Geometric instability catalyzes mitochondrial fission. Mol Biol Cell 2018; 30:160-168. [PMID: 30379601 PMCID: PMC6337907 DOI: 10.1091/mbc.e18-01-0018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The mitochondrial membrane undergoes extreme remodeling during fission. While a few membrane-squeezing proteins are recognized as the key drivers of fission, there is a growing body of evidence that strongly suggests that conical lipids play a critical role in regulating mitochondrial morphology and fission. However, the mechanisms by which proteins and lipids cooperate to execute fission have not been quantitatively investigated. Here, we computationally model the squeezing of the largely tubular mitochondrion and show that proteins and conical lipids can act synergistically to trigger buckling instability and achieve extreme constriction. More remarkably, the study reveals that the conical lipids can act with different fission proteins to induce hierarchical instabilities and create increasingly narrow and stable constrictions. We reason that this geometric plasticity imparts significant robustness to the fission reaction by arresting the elastic tendency of the membrane to rebound during protein polymerization and depolymerization cycles. Our in vitro study validates protein–lipid cooperativity in constricting membrane tubules. Overall, our work presents a general mechanism for achieving drastic topological remodeling in cellular membranes.
Collapse
Affiliation(s)
- Ehsan Irajizad
- Department of Mechanical Engineering, University of Houston, Houston, TX 77204
| | - Rajesh Ramachandran
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106
| | - Ashutosh Agrawal
- Department of Mechanical Engineering, University of Houston, Houston, TX 77204
| |
Collapse
|
6
|
Jimbo T, Sakuma Y, Urakami N, Ziherl P, Imai M. Role of Inverse-Cone-Shape Lipids in Temperature-Controlled Self-Reproduction of Binary Vesicles. Biophys J 2016; 110:1551-1562. [PMID: 27074680 DOI: 10.1016/j.bpj.2016.02.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 02/17/2016] [Accepted: 02/19/2016] [Indexed: 11/29/2022] Open
Abstract
We investigate a temperature-driven recursive division of binary giant unilamellar vesicles (GUVs). During the heating step of the heating-cooling cycle, the spherical mother vesicle deforms to a budded limiting shape using up the excess area produced by the chain melting of the lipids and then splits off into two daughter vesicles. Upon cooling, the daughter vesicle opens a pore and recovers the spherical shape of the mother vesicle. Our GUVs are composed of DLPE (1,2-dilauroyl-sn-glycero-3-phosphoethanolamine) and DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine). During each cycle, vesicle deformation is monitored by a fast confocal microscope and the images are analyzed to obtain the time evolution of reduced volume and reduced monolayer area difference as the key geometric parameters that quantify vesicle shape. By interpreting the deformation pathway using the area-difference elasticity theory, we conclude that vesicle division relies on (1) a tiny asymmetric distribution of DLPE within the bilayer, which controls the observed deformation from the sphere to the budded shape; and (2) redistribution of DLPE during the deformation-division stage, which ensures that the process is recursive. The spontaneous coupling between membrane curvature and PE lipid distribution is responsible for the observed recursive division of GUVs. These results shed light on the mechanisms of vesicle self-reproduction.
Collapse
Affiliation(s)
- Takehiro Jimbo
- Department of Physics, Tohoku University, Aoba, Sendai, Japan
| | - Yuka Sakuma
- Department of Physics, Tohoku University, Aoba, Sendai, Japan
| | - Naohito Urakami
- Department of Physics and Information Sciences, Yamaguchi University, Yamaguchi, Japan
| | - Primož Ziherl
- Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana, Slovenia; Jožef Stefan Institute, Ljubljana, Slovenia
| | - Masayuki Imai
- Department of Physics, Tohoku University, Aoba, Sendai, Japan.
| |
Collapse
|
7
|
Sakuma Y, Imai M. From vesicles to protocells: the roles of amphiphilic molecules. Life (Basel) 2015; 5:651-75. [PMID: 25738256 PMCID: PMC4390873 DOI: 10.3390/life5010651] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 02/11/2015] [Accepted: 02/24/2015] [Indexed: 02/05/2023] Open
Abstract
It is very challenging to construct protocells from molecular assemblies. An important step in this challenge is the achievement of vesicle dynamics that are relevant to cellular functions, such as membrane trafficking and self-reproduction, using amphiphilic molecules. Soft matter physics will play an important role in the development of vesicles that have these functions. Here, we show that simple binary phospholipid vesicles have the potential to reproduce the relevant functions of adhesion, pore formation and self-reproduction of vesicles, by coupling the lipid geometries (spontaneous curvatures) and the phase separation. This achievement will elucidate the pathway from molecular assembly to cellular life.
Collapse
Affiliation(s)
- Yuka Sakuma
- Department of Physics, Tohoku University, Aoba, Sendai 980-8578, Japan.
| | - Masayuki Imai
- Department of Physics, Tohoku University, Aoba, Sendai 980-8578, Japan.
| |
Collapse
|
8
|
Liu Y, Li M, Yang Y, Xia Y, Nieh MP. The effects of temperature, salinity, concentration and PEGylated lipid on the spontaneous nanostructures of bicellar mixtures. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:1871-80. [DOI: 10.1016/j.bbamem.2014.02.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 12/23/2013] [Accepted: 02/11/2014] [Indexed: 10/25/2022]
|
9
|
Sakuma Y, Taniguchi T, Kawakatsu T, Imai M. Tubular membrane formation of binary giant unilamellar vesicles composed of cylinder and inverse-cone-shaped lipids. Biophys J 2014; 105:2074-81. [PMID: 24209852 DOI: 10.1016/j.bpj.2013.09.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 08/20/2013] [Accepted: 09/09/2013] [Indexed: 11/28/2022] Open
Abstract
We have succeeded in controlling tubular membrane formations in binary giant unilamellar vesicles (GUVs) using a simple temperature changing between the homogeneous one-phase region and the two-phase coexistence region. The binary GUV is composed of inverse-cone (bulky hydrocarbon chains and a small headgroup) and cylinder-shaped lipids. When the temperature was set in the two-phase coexistence region, the binary GUV had a spherical shape with solidlike domains. By increasing the temperature to the homogeneous one-phase region, the excess area created by the chain melting of the lipid produced tubes inside the GUV. The tubes had a radius on the micrometer scale and were stable in the one-phase region. When we again decreased the temperature to the two-phase coexisting region, the tubes regressed and the GUVs recovered their phase-separated spherical shape. We infer that the tubular formation was based on the mechanical balance of the vesicle membrane (spontaneous tension) coupled with the asymmetric distribution of the inverse-cone-shaped lipids between the inner and outer leaflets of the vesicle (lipid sorting).
Collapse
Affiliation(s)
- Yuka Sakuma
- Department of Physics, Tohoku University, Aoba, Sendai, Japan.
| | | | | | | |
Collapse
|
10
|
Sakuma Y, Imai M. Model system of self-reproducing vesicles. PHYSICAL REVIEW LETTERS 2011; 107:198101. [PMID: 22181648 DOI: 10.1103/physrevlett.107.198101] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Indexed: 05/31/2023]
Abstract
Development of self-reproducing vesicle systems is the first step for autopoietic cycles. We established a model self-reproducing vesicle system without the membrane molecule synthesis route. The model vesicle composed of cylinder- and inverse-cone-shaped lipids formed inclusion vesicles inside the mother vesicle, and the inclusion vesicles were then expelled by a temperature cycling. By changing the vesicle composition, the mother vesicles showed a budding-type self-reproduction pathway. A key concept of this system is the coupling of the main-chain transition and the shape of lipids.
Collapse
Affiliation(s)
- Yuka Sakuma
- Department of Physics, Ochanomizu University, Bunkyo, Tokyo 112-8610, Japan
| | | |
Collapse
|