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Oshima A, Nakanishi K, Kasai N, Nakashima H, Tsumoto K, Sumitomo K. Mechanism of Budded Virus Envelope Fusion into a Planar Bilayer Lipid Membrane on a SiO 2 Substrate. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:5464-5471. [PMID: 35436122 DOI: 10.1021/acs.langmuir.1c03456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Artificial planar bilayer lipid membranes (BLMs) are simple models of cellular systems under physically and chemically controlled conditions, and they have been used to investigate membrane protein activity. Baculovirus-budded virus (BV) systems can express recombinant membrane proteins. In this study, aiming for membrane protein reconstitution, we examined the fusion of BVs containing recombinant membrane proteins into artificial planar BLMs on a Si microwell substrate. BV fusion with the BLMs depended on the pH of the solution, and it was enhanced at lower pH. Based on fluorescence recovery after photobleaching (FRAP) measurement, the fusion state of BVs was evaluated, and full fusion at low pH was confirmed. The fluorescent labeling the membrane proteins was also observed in the freestanding part of the BLMs as well as in the supported part. These results demonstrate the effectiveness of BLMs as a platform to examine detailed fusion dynamics of BVs. Furthermore, this study revealed that the fusion of BVs is a promising method for reconstituting membrane proteins to artificial freestanding BLMs for the development of biodevices with which we can examine membrane protein activity.
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Affiliation(s)
- Azusa Oshima
- NTT Basic Research Laboratories and Bio-Medical Informatics Research Center, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Kohei Nakanishi
- Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho, Tsu, Mie 514-8507, Japan
| | - Nahoko Kasai
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Hiroshi Nakashima
- NTT Basic Research Laboratories and Bio-Medical Informatics Research Center, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Kanta Tsumoto
- Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho, Tsu, Mie 514-8507, Japan
| | - Koji Sumitomo
- University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
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Oshima A, Nakashima H, Sumitomo K. Evaluation of Lateral Diffusion of Lipids in Continuous Membranes between Freestanding and Supported Areas by Fluorescence Recovery after Photobleaching. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:11725-11734. [PMID: 31407907 DOI: 10.1021/acs.langmuir.9b01595] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The lateral diffusion of lipids is a key factor when functionalizing artificial planar bilayer lipid membranes (BLMs). Fluorescence recovery after photobleaching (FRAP) is an established method for evaluating the fluidity of BLMs by the quantitative determination of the diffusion coefficient. However, a BLM with a uniform diffusion coefficient is usually assumed for analysis. In addition, when the BLM to be evaluated is small, the spread of a bleached circle caused by lateral diffusion during the bleaching process and the divergence of the laser used for bleaching interfere with the quantitative analysis. In this study, a numerical calculation was adopted to make it possible to analyze the continuous BLM between freestanding and supported areas, where the diffusion coefficients change depending on the presence or absence of an interaction with the substrate. A quantitative evaluation independent of such bleaching conditions as the bleaching diameter was also ensured by incorporating the spreading effect of the bleached circle in the calculation, which was employed to analyze a freestanding BLM with a diameter of only a few micrometers. By comparing calculations and experiments on FRAP recovery curves, we found that there are multiple diffusion elements and high diffusion barriers at the boundary between the freestanding and supported areas in a BLM over a SiO2/Si microwell substrate.
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Affiliation(s)
- Azusa Oshima
- NTT Basic Research Laboratories , NTT Corporation , 3-1 Morinosato Wakamiya , Atsugi , Kanagawa 243-0198 , Japan
| | - Hiroshi Nakashima
- NTT Basic Research Laboratories , NTT Corporation , 3-1 Morinosato Wakamiya , Atsugi , Kanagawa 243-0198 , Japan
| | - Koji Sumitomo
- University of Hyogo , 2167 Shosha , Himeji , Hyogo 671-2280 , Japan
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Diederichs T, Nguyen QH, Urban M, Tampé R, Tornow M. Transparent Nanopore Cavity Arrays Enable Highly Parallelized Optical Studies of Single Membrane Proteins on Chip. NANO LETTERS 2018; 18:3901-3910. [PMID: 29741381 DOI: 10.1021/acs.nanolett.8b01252] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Membrane proteins involved in transport processes are key targets for pharmaceutical research and industry. Despite continuous improvements and new developments in the field of electrical readouts for the analysis of transport kinetics, a well-suited methodology for high-throughput characterization of single transporters with nonionic substrates and slow turnover rates is still lacking. Here, we report on a novel architecture of silicon chips with embedded nanopore microcavities, based on a silicon-on-insulator technology for high-throughput optical readouts. Arrays containing more than 14 000 inverted-pyramidal cavities of 50 femtoliter volumes and 80 nm circular pore openings were constructed via high-resolution electron-beam lithography in combination with reactive ion etching and anisotropic wet etching. These cavities feature both, an optically transparent bottom and top cap. Atomic force microscopy analysis reveals an overall extremely smooth chip surface, particularly in the vicinity of the nanopores, which exhibits well-defined edges. Our unprecedented transparent chip design provides parallel and independent fluorescent readout of both cavities and buffer reservoir for unbiased single-transporter recordings. Spreading of large unilamellar vesicles with efficiencies up to 96% created nanopore-supported lipid bilayers, which are stable for more than 1 day. A high lipid mobility in the supported membrane was determined by fluorescent recovery after photobleaching. Flux kinetics of α-hemolysin were characterized at single-pore resolution with a rate constant of 0.96 ± 0.06 × 10-3 s-1. Here, we deliver an ideal chip platform for pharmaceutical research, which features high parallelism and throughput, synergistically combined with single-transporter resolution.
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Affiliation(s)
- Tim Diederichs
- Institute of Biochemistry, Biocenter , Goethe University Frankfurt , Max-von-Laue-Str. 9 , 60438 Frankfurt/M. , Germany
| | - Quoc Hung Nguyen
- Molecular Electronics , Technical University of Munich , Theresienstrasse 90 , 80333 Munich , Germany
| | - Michael Urban
- Institute of Biochemistry, Biocenter , Goethe University Frankfurt , Max-von-Laue-Str. 9 , 60438 Frankfurt/M. , Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter , Goethe University Frankfurt , Max-von-Laue-Str. 9 , 60438 Frankfurt/M. , Germany
- Cluster of Excellence Frankfurt (CEF) Macromolecular Complexes ; Goethe University Frankfurt , Max-von-Laue-Strasse 9 , 60438 Frankfurt/M. , Germany
| | - Marc Tornow
- Molecular Electronics , Technical University of Munich , Theresienstrasse 90 , 80333 Munich , Germany
- Fraunhofer Research Institution for Microsystems and Solid State Technologies (EMFT) , Hansastrasse 27d , 80686 Munich , Germany
- Center for NanoScience (CeNS) , Ludwig-Maximilians-University , Geschwister-Scholl Platz 1 , 80539 Munich , Germany
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Sumitomo K, Oshima A. Liquid-Ordered/Liquid-Crystalline Phase Separation at a Lipid Bilayer Suspended over Microwells. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:13277-13283. [PMID: 29088540 DOI: 10.1021/acs.langmuir.7b02156] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The localization of liquid-ordered (Lo) and liquid-crystalline (Lα) phase domains on a silicon substrate with a microwell array is investigated. Although the phase separation of the Lo and Lα phases on both a giant unilamellar vesicle (GUV) and a supported membrane remains stable for a long time, the lateral diffusion of lipids across each domain boundary occurs quickly. Since the phase separation and domain arrangement are governed by the stiffness and lateral tension of the lipid membrane, the phase separation is rearranged on a micropatterned substrate. Similar phase separation of the Lo and Lα phases is observed at a lipid membrane suspended over a microwell. However, the Lα phase is preferred at a suspended membrane, and saturated lipids and cholesterol are excluded toward the supporting membrane on the periphery. Since the Lo domain area is reduced by anisotropic diffusion through the boundary between the suspended and supported membranes, a very slow reduction rate with a linear functional relation is observed. Finally, a localized Lα phase domain is observed at a membrane suspended over a microwell, which is surrounded by an Lo phase supported membrane.
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Affiliation(s)
- Koji Sumitomo
- NTT Basic Research Laboratories, NTT Corporation , 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Azusa Oshima
- NTT Basic Research Laboratories, NTT Corporation , 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan
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Lipid bilayer membrane technologies: A review on single-molecule studies of DNA sequencing by using membrane nanopores. Mikrochim Acta 2017. [DOI: 10.1007/s00604-017-2321-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abstract
This chapter provides a review of different advanced methods that help to increase the success rate of a crystallization project, by producing larger and higher quality single crystals for determination of macromolecular structures by crystallographic methods. For this purpose, the chapter is divided into three parts. The first part deals with the fundamentals for understanding the crystallization process through different strategies based on physical and chemical approaches. The second part presents new approaches involved in more sophisticated methods not only for growing protein crystals but also for controlling the size and orientation of crystals through utilization of electromagnetic fields and other advanced techniques. The last section deals with three different aspects: the importance of microgravity, the use of ligands to stabilize proteins, and the use of microfluidics to obtain protein crystals. All these advanced methods will allow the readers to obtain suitable crystalline samples for high-resolution X-ray and neutron crystallography.
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Affiliation(s)
- Abel Moreno
- Instituto de Química, Universidad Nacional Autónoma de Mexico, Av. Universidad 3000, Cd.Mx., Mexico City, 04510, Mexico.
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