1
|
Zhang Y, Tunuguntla RH, Choi PO, Noy A. Real-time dynamics of carbon nanotube porins in supported lipid membranes visualized by high-speed atomic force microscopy. Philos Trans R Soc Lond B Biol Sci 2018. [PMID: 28630162 DOI: 10.1098/rstb.2016.0226] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In-plane mobility of proteins in lipid membranes is one of the fundamental mechanisms supporting biological functionality. Here we use high-speed atomic force microscopy (HS-AFM) to show that a novel type of biomimetic channel-carbon nanotube porins (CNTPs)-is also laterally mobile in supported lipid membranes, mimicking biological protein behaviour. HS-AFM can capture real-time dynamics of CNTP motion in the supported lipid bilayer membrane, build long-term trajectories of the CNTP motion and determine the diffusion coefficients associated with this motion. Our analysis shows that diffusion coefficients of CNTPs fall into the same range as those of proteins in supported lipid membranes. CNTPs in HS-AFM experiments often exhibit 'directed' diffusion behaviour, which is common for proteins in live cell membranes.This article is part of the themed issue 'Membrane pores: from structure and assembly, to medicine and technology'.
Collapse
Affiliation(s)
- Yuliang Zhang
- Biology and Biotechnology Division, Physics and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Ramya H Tunuguntla
- Biology and Biotechnology Division, Physics and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Pyung-On Choi
- Biology and Biotechnology Division, Physics and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Aleksandr Noy
- Biology and Biotechnology Division, Physics and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA .,School of Natural Sciences, University of California Merced, Merced, CA 95343, USA
| |
Collapse
|
2
|
Bampoulis P, Witteveen JP, Kooij ES, Lohse D, Poelsema B, Zandvliet HJW. Structure and Dynamics of Confined Alcohol-Water Mixtures. ACS Nano 2016; 10:6762-8. [PMID: 27337245 DOI: 10.1021/acsnano.6b02333] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The effect of confinement between mica and graphene on the structure and dynamics of alcohol-water mixtures has been studied in situ and in real time at the molecular level by atomic force microscopy (AFM) at room temperature. AFM images reveal that the adsorbed molecules are segregated into faceted alcohol-rich islands on top of an ice layer on mica, surrounded by a pre-existing multilayer water-rich film. These faceted islands are in direct contact with the graphene surface, revealing a preferred adsorption site. Moreover, alcohol adsorption at low relative humidity (RH) reveals a strong preference of the alcohol molecules for the ordered ice interface. The growth dynamics of the alcohol islands is governed by supersaturation, temperature, the free energy of attachment of molecules to the island edge and two-dimensional (2D) diffusion. The measured diffusion coefficients display a size dependence on the molecular size of the alcohols, and are about 6 orders of magnitude smaller than the bulk diffusion coefficients, demonstrating the effect of confinement on the behavior of the alcohols. These experimental results provide new insights into the behavior of multicomponent fluids in confined geometries, which is of paramount importance in nanofluidics and biology.
Collapse
Affiliation(s)
- Pantelis Bampoulis
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500AE Enschede, The Netherlands
- Physics of Fluids and J.M. Burgers Centre for Fluid Mechanics, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500AE Enschede, The Netherlands
| | - Jorn P Witteveen
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500AE Enschede, The Netherlands
| | - E Stefan Kooij
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500AE Enschede, The Netherlands
| | - Detlef Lohse
- Physics of Fluids and J.M. Burgers Centre for Fluid Mechanics, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500AE Enschede, The Netherlands
- Max Planck Institute for Dynamics and Self-Organization , Am Fassberg, 37077 Göttingen, Germany
| | - Bene Poelsema
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500AE Enschede, The Netherlands
| | - Harold J W Zandvliet
- Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente , P.O. Box 217, 7500AE Enschede, The Netherlands
| |
Collapse
|
3
|
Wilke N, Maggio B. Electrostatic field effects on membrane domain segregation and on lateral diffusion. Biophys Rev 2011; 3:185-192. [PMID: 28510045 DOI: 10.1007/s12551-011-0057-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 08/20/2011] [Indexed: 12/17/2022] Open
Abstract
Natural membranes are organized structures of neutral and charged molecules bearing dipole moments which generate local non-homogeneous electric fields. When subjected to such fields, the molecules experience net forces that can modify the lipid and protein organization, thus modulating cell activities and influencing (or even dominating) the biological functions. The energetics of electrostatic interactions in membranes is a long-range effect which can vary over distance within r-1 to r-3. In the case of a dipole interacting with a plane of dipoles, e.g. a protein interacting with a lipid domain, the interaction is stronger than two punctual dipoles and depends on the size of the domain. In this article, we review several contributions on how electrostatic interactions in the membrane plane can modulate the phase behavior, surface topography and mechanical properties in monolayers and bilayers.
Collapse
Affiliation(s)
- Natalia Wilke
- Centro de Investigaciones de Química Bológica de Córdoba (CIQUIBIC-CONICET), Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina. .,CIQUIBIC, Dpto. de Química Biológica, Fac. de Cs. Químicas, UNC, Pabellón Argentina, Ciudad Universitaria, X5000HUA, Córdoba, Argentina.
| | - Bruno Maggio
- Centro de Investigaciones de Química Bológica de Córdoba (CIQUIBIC-CONICET), Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| |
Collapse
|