1
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Allahyarov E, Löwen H. Electric field-induced clustering in nanocomposite films of highly polarizable inclusions. J Colloid Interface Sci 2024; 668:587-598. [PMID: 38691967 DOI: 10.1016/j.jcis.2024.04.134] [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: 02/01/2024] [Revised: 04/04/2024] [Accepted: 04/19/2024] [Indexed: 05/03/2024]
Abstract
A nanocomposite film containing highly polarizable inclusions in a fluid background is explored when an external electric field is applied perpendicular to the planar film. For small electric fields, the induced dipole moments of the inclusions are all polarized in field direction, resulting in a mutual repulsion between the inclusions. Here we show that this becomes qualitatively different for high fields: the total system self-organizes into a state which contains both polarizations, parallel and antiparallel to the external field such that a fraction of the inclusions is counter-polarized to the electric field direction. We attribute this unexpected counter-polarization to the presence of neighboring dipoles which are highly polarized and locally revert the direction of the total electric field. Since dipoles with opposite moments are attractive, the system shows a wealth of novel equilibrium structures for varied inclusion density and electric field strength. These include fluids and solids with homogeneous polarizations as well as equilibrium clusters and demixed states with two different polarization signatures. Based on computer simulations of an linearized polarization model, our results can guide the control of nanocomposites for various applications, including sensing external fields, directing light within plasmonic materials, and controlling the functionality of biological membranes.
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Affiliation(s)
- Elshad Allahyarov
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine Universität Düsseldorf, Universitätstrasse 1, 40225 Düsseldorf, Germany; Theoretical Department, Joint Institute for High Temperatures, Russian Academy of Sciences (IVTAN), 13/19 Izhorskaya street, Moscow 125412, Russia; Department of Physics, Case Western Reserve University, Cleveland, OH 44106-7202, United States.
| | - Hartmut Löwen
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine Universität Düsseldorf, Universitätstrasse 1, 40225 Düsseldorf, Germany
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2
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Redwan DA, Du K, Yong X. Probing wrapping dynamics of spherical nanoparticles by 3D vesicles using force-based simulations. SOFT MATTER 2024; 20:4548-4560. [PMID: 38502376 DOI: 10.1039/d3sm01600e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
Nanoparticles present in various environments can interact with living organisms, potentially leading to deleterious effects. Understanding how these nanoparticles interact with cell membranes is crucial for rational assessment of their impact on diverse biological processes. While previous research has explored particle-membrane interactions, the dynamic processes of particle wrapping by fluid vesicles remain incompletely understood. In this study, we introduce a force-based, continuum-scale model utilizing triangulated mesh representation and discrete differential geometry to investigate particle-vesicle interaction dynamics. Our model captures the transformation of vesicle shape and nanoparticle wrapping by calculating the forces arising from membrane bending energy and particle adhesion energy. Inspired by cell phagocytosis of large particles, we focus on establishing a quantitative understanding of large-scale vesicle deformation induced by the interaction with particles of comparable sizes. We first examine the interactions between spherical vesicles and individual nanospheres, both externally and internally, and quantify energy landscapes across different wrapping fractions of the nanoparticles. Furthermore, we explore multiple particle interactions with biologically relevant fluid vesicles with nonspherical shapes. Our study reveals that initial particle positions and interaction sequences are critical in determining the final equilibrium shapes of the vesicle-particle complexes in these interactions. These findings emphasize the importance of nanoparticle positioning and wrapping fractions in the dynamics of particle-vesicle interactions, providing crucial insights for future research in the field.
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Affiliation(s)
- Didarul Ahasan Redwan
- Department of Mechanical Engineering, Binghamton University, Binghamton, New York 13902, USA.
| | - Ke Du
- Department of Chemical and Environmental Engineering, University of California Riverside, Riverside, California 92521, USA
| | - Xin Yong
- Department of Mechanical Engineering, Binghamton University, Binghamton, New York 13902, USA.
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3
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Orlikowska-Rzeznik H, Versluis J, Bakker HJ, Piatkowski L. Cholesterol Changes Interfacial Water Alignment in Model Cell Membranes. J Am Chem Soc 2024; 146:13151-13162. [PMID: 38687869 PMCID: PMC11099968 DOI: 10.1021/jacs.4c00474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 04/20/2024] [Accepted: 04/22/2024] [Indexed: 05/02/2024]
Abstract
The nanoscopic layer of water that directly hydrates biological membranes plays a critical role in maintaining the cell structure, regulating biochemical processes, and managing intermolecular interactions at the membrane interface. Therefore, comprehending the membrane structure, including its hydration, is essential for understanding the chemistry of life. While cholesterol is a fundamental lipid molecule in mammalian cells, influencing both the structure and dynamics of cell membranes, its impact on the structure of interfacial water has remained unknown. We used surface-specific vibrational sum-frequency generation spectroscopy to study the effect of cholesterol on the structure and hydration of monolayers of the lipids 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), and egg sphingomyelin (SM). We found that for the unsaturated lipid DOPC, cholesterol intercalates in the membrane without significantly changing the orientation of the lipid tails and the orientation of the water molecules hydrating the headgroups of DOPC. In contrast, for the saturated lipids DPPC and SM, the addition of cholesterol leads to clearly enhanced packing and ordering of the hydrophobic tails. It is also observed that the orientation of the water hydrating the lipid headgroups is enhanced upon the addition of cholesterol. These results are important because the orientation of interfacial water molecules influences the cell membranes' dipole potential and the strength and specificity of interactions between cell membranes and peripheral proteins and other biomolecules. The lipid nature-dependent role of cholesterol in altering the arrangement of interfacial water molecules offers a fresh perspective on domain-selective cellular processes, such as protein binding.
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Affiliation(s)
- Hanna Orlikowska-Rzeznik
- Faculty
of Materials Engineering and Technical Physics, Poznan University of Technology, 60-965 Poznan, Poland
| | - Jan Versluis
- AMOLF,
Ultrafast Spectroscopy, 1098 XG Amsterdam, The Netherlands
| | - Huib J. Bakker
- AMOLF,
Ultrafast Spectroscopy, 1098 XG Amsterdam, The Netherlands
| | - Lukasz Piatkowski
- Faculty
of Materials Engineering and Technical Physics, Poznan University of Technology, 60-965 Poznan, Poland
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4
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Yu C, Shang P, Guo Y, Zhang Z. In Situ Heterodyne-Detected Second-Harmonic Generation Study of the Influence of Cholesterol on Dye Molecule Adsorption on Lipid Membrane. J Phys Chem B 2024; 128:1892-1899. [PMID: 38354410 DOI: 10.1021/acs.jpcb.3c07130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
Cholesterol plays an essential role in regulating the functionality of biomembranes. This study employed in situ second-harmonic generation (SHG) to investigate the adsorption behavior of the dye molecule 4-(4-(diethylamino)styryl)-N-methyl-pyridinium iodide (D289) on a biomimic membrane composed of 1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (sodium salt) (DPPG) and cholesterol. The time-dependent polarization SHG intensity exhibited an initial rapid increase, followed by a subsequent decline. The initial increased SHG intensity is responsible for the electrostatic interaction-driven adsorption of D289 onto the membrane, while the decrease in the SHG signal results from the broadening of the orientation distribution within the membrane. Heterodyne-detected SHG (HD-SHG) measurements demonstrated that the adsorption of dye molecules influenced the phase of the induced electric field. The interfacial potential Φ(0) as a function of time was measured, and we found that even after reaching a stable Stern layer state, the diffusion layer continued to exhibit a dynamic change. This study offers a comprehensive understanding of the influence of cholesterol on adsorption, reorientation dynamics, and dynamic changes in the reorientation of water in the diffusion layer.
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Affiliation(s)
- Changhui Yu
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy Sciences, Beijing 100049, China
| | - Peng Shang
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy Sciences, Beijing 100049, China
| | - Yuan Guo
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy Sciences, Beijing 100049, China
| | - Zhen Zhang
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy Sciences, Beijing 100049, China
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5
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Matsuki Y, Iwamoto M, Oiki S. Asymmetric Lipid Bilayers and Potassium Channels Embedded Therein in the Contact Bubble Bilayer. Methods Mol Biol 2024; 2796:1-21. [PMID: 38856892 DOI: 10.1007/978-1-0716-3818-7_1] [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: 06/11/2024]
Abstract
Cell membranes are highly intricate systems comprising numerous lipid species and membrane proteins, where channel proteins, lipid molecules, and lipid bilayers, as continuous elastic fabric, collectively engage in multi-modal interplays. Owing to the complexity of the native cell membrane, studying the elementary processes of channel-membrane interactions necessitates a bottom-up approach starting from forming simplified synthetic membranes. This is the rationale for establishing an in vitro membrane reconstitution system consisting of a lipid bilayer with a defined lipid composition and a channel molecule. Recent technological advancements have facilitated the development of asymmetric membranes, and the contact bubble bilayer (CBB) method allows single-channel current recordings under arbitrary lipid compositions in asymmetric bilayers. Here, we present an experimental protocol for the formation of asymmetric membranes using the CBB method. The KcsA potassium channel is a prototypical model channel with huge structural and functional information and thus serves as a reporter of membrane actions on the embedded channels. We demonstrate specific interactions of anionic lipids in the inner leaflet. Considering that the local lipid composition varies steadily in cell membranes, we `present a novel lipid perfusion technique that allows rapidly changing the lipid composition while monitoring the single-channel behavior. Finally, we demonstrate a leaflet perfusion method for modifying the composition of individual leaflets. These techniques with custom synthetic membranes allow for variable experiments, providing crucial insights into channel-membrane interplay in cell membranes.
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Affiliation(s)
- Yuka Matsuki
- Department of Anesthesiology and Reanimatology, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Masayuki Iwamoto
- Department of Molecular Neuroscience, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Shigetoshi Oiki
- Biomedical Imaging Research Center, University of Fukui, Fukui, Japan.
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6
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Mai TL, Derreumaux P, Nguyen PH. Structure and Elasticity of Mitochondrial Membranes: A Molecular Dynamics Simulation Study. J Phys Chem B 2023; 127:10778-10791. [PMID: 38084584 DOI: 10.1021/acs.jpcb.3c05112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
Mitochondria are known as the powerhouse of the cell because they produce energy in the form of adenosine triphosphate. They also have other crucial functions such as regulating apoptosis, calcium homeostasis, and reactive oxygen species production. To perform these diverse functions, mitochondria adopt specific structures and frequently undergo dynamic shape changes, indicating that their mechanical properties play an essential role in their functions. To gain a detailed understanding at the molecular level of the structure and mechanical properties of mitochondria, we carry out atomistic molecular dynamics simulations for three inner mitochondrial membranes and three outer mitochondrial membrane models. These models take into account variations in cardiolipin and cholesterol concentrations as well as the symmetry/asymmetry between the two leaflets. Our simulations allow us to calculate various structural quantities and the bending, twisting, and tilting elastic moduli of the membrane models. Our results indicate that the structures of the inner and outer mitochondrial membranes are quite similar and do not depend much on the variation in lipid compositions. However, the bending modulus of the membranes increases with increasing concentrations of cardiolipin or cholesterol but decreases with a membrane asymmetry. Notably, we found that the dipole potential of the membrane increases with an increasing cardiolipin concentration. Finally, possible roles of cardiolipin in regulating ion and proton currents and maintaining the cristate are discussed in some details.
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Affiliation(s)
- Thi Ly Mai
- CNRS, Université Paris Cité, UPR9080, Laboratoire de Biochimie Théorique, Institute de Biologie Physico-Chimique, Fondation Edmond de Rothschild, 13 rue Pierre et Marie Curie, Paris 75005, France
| | - Philippe Derreumaux
- CNRS, Université Paris Cité, UPR9080, Laboratoire de Biochimie Théorique, Institute de Biologie Physico-Chimique, Fondation Edmond de Rothschild, 13 rue Pierre et Marie Curie, Paris 75005, France
- Institut Universitaire de France (IUF), Paris 75005, France
| | - Phuong H Nguyen
- CNRS, Université Paris Cité, UPR9080, Laboratoire de Biochimie Théorique, Institute de Biologie Physico-Chimique, Fondation Edmond de Rothschild, 13 rue Pierre et Marie Curie, Paris 75005, France
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7
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Clarke RJ. Electrostatic switch mechanisms of membrane protein trafficking and regulation. Biophys Rev 2023; 15:1967-1985. [PMID: 38192346 PMCID: PMC10771482 DOI: 10.1007/s12551-023-01166-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 11/17/2023] [Indexed: 01/10/2024] Open
Abstract
Lipid-protein interactions are normally classified as either specific or general. Specific interactions refer to lipid binding to specific binding sites within a membrane protein, thereby modulating the protein's thermal stability or kinetics. General interactions refer to indirect effects whereby lipids affect membrane proteins by modulating the membrane's physical properties, e.g., its fluidity, thickness, or dipole potential. It is not widely recognized that there is a third distinct type of lipid-protein interaction. Intrinsically disordered N- or C-termini of membrane proteins can interact directly but nonspecifically with the surrounding membrane. Many peripheral membrane proteins are held to the cytoplasmic surface of the plasma membrane via a cooperative combination of two forces: hydrophobic anchoring and electrostatic attraction. An acyl chain, e.g., myristoyl, added post-translationally to one of the protein's termini inserts itself into the lipid matrix and helps hold peripheral membrane proteins onto the membrane. Electrostatic attraction occurs between positively charged basic amino acid residues (lysine and arginine) on one of the protein's terminal tails and negatively charged phospholipid head groups, such as phosphatidylserine. Phosphorylation of either serine or tyrosine residues on the terminal tails via regulatory protein kinases allows for an electrostatic switch mechanism to control trafficking of the protein. Kinase action reduces the positive charge on the protein's tail, weakening the electrostatic attraction and releasing the protein from the membrane. A similar mechanism regulates many integral membrane proteins, but here only electrostatic interactions are involved, and the electrostatic switch modulates protein activity by altering the stabilities of different protein conformational states.
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Affiliation(s)
- Ronald J. Clarke
- School of Chemistry, University of Sydney, Sydney, NSW 2006 Australia
- The University of Sydney Nano Institute, Sydney, NSW 2006 Australia
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8
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Zakany F, Mándity IM, Varga Z, Panyi G, Nagy P, Kovacs T. Effect of the Lipid Landscape on the Efficacy of Cell-Penetrating Peptides. Cells 2023; 12:1700. [PMID: 37443733 PMCID: PMC10340183 DOI: 10.3390/cells12131700] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/16/2023] [Accepted: 06/20/2023] [Indexed: 07/15/2023] Open
Abstract
Every cell biological textbook teaches us that the main role of the plasma membrane is to separate cells from their neighborhood to allow for a controlled composition of the intracellular space. The mostly hydrophobic nature of the cell membrane presents an impenetrable barrier for most hydrophilic molecules larger than 1 kDa. On the other hand, cell-penetrating peptides (CPPs) are capable of traversing this barrier without compromising membrane integrity, and they can do so on their own or coupled to cargos. Coupling biologically and medically relevant cargos to CPPs holds great promise of delivering membrane-impermeable drugs into cells. If the cargo is able to interact with certain cell types, uptake of the CPP-drug complex can be tailored to be cell-type-specific. Besides outlining the major membrane penetration pathways of CPPs, this review is aimed at deciphering how properties of the membrane influence the uptake mechanisms of CPPs. By summarizing an extensive body of experimental evidence, we argue that a more ordered, less flexible membrane structure, often present in the very diseases planned to be treated with CPPs, decreases their cellular uptake. These correlations are not only relevant for understanding the cellular biology of CPPs, but also for rationally improving their value in translational or clinical applications.
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Affiliation(s)
- Florina Zakany
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (F.Z.); (Z.V.); (G.P.)
| | - István M. Mándity
- Department of Organic Chemistry, Faculty of Pharmacy, Semmelweis University, 1085 Budapest, Hungary;
- TTK Lendület Artificial Transporter Research Group, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, 1117 Budapest, Hungary
| | - Zoltan Varga
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (F.Z.); (Z.V.); (G.P.)
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (F.Z.); (Z.V.); (G.P.)
| | - Peter Nagy
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (F.Z.); (Z.V.); (G.P.)
| | - Tamas Kovacs
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (F.Z.); (Z.V.); (G.P.)
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9
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Kundu A, Yamaguchi S, Tahara T. Local pH at Nonionic and Zwitterionic Lipid/Water Interfaces Revealed by Heterodyne-Detected Electronic Sum-Frequency Generation: A Unified View to Predict Interfacial pH of Biomembranes. J Phys Chem B 2023; 127:5445-5452. [PMID: 37308160 PMCID: PMC10292198 DOI: 10.1021/acs.jpcb.3c02002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 05/20/2023] [Indexed: 06/14/2023]
Abstract
For biomembranes, which are composed of neutral as well as charged lipids, the local pH at lipid/water interfaces is extremely important in their structural formation and functional activity. In our previous study of the charged lipid/water interfaces, we found that the local pH at the interface is governed by the positive or negative sign of the charge of the lipid: i.e., the local pH is dictated by the repulsive or attractive electrostatic interaction between the charged lipid headgroup and the proton. Because of the lack of net charge in the headgroup of the neutral lipid, the factor determining the local pH at neutral lipid/water interfaces is less straightforward, and therefore it is more challenging to predict the local pH. Here we apply heterodyne-detected electronic sum frequency generation (HD-ESFG) spectroscopy to nonionic and zwitterionic lipids to investigate the local pH at the neutral lipid/water interfaces. The obtained results indicate that the local pH at the nonionic lipid/water interface is higher than in bulk water by 0.8 whereas the local pH at the zwitterionic lipid/water interface is lower by 0.6, although the latter is subject to significant uncertainty. The present HD-ESFG study on neutral lipids, combined with the previous study on charged lipids, presents a unified view to consider the local pH at biomembranes based on the balance between the electrostatic interaction and the hydrophobicity provided by the lipid.
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Affiliation(s)
- Achintya Kundu
- Molecular
Spectroscopy Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Shoichi Yamaguchi
- Molecular
Spectroscopy Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
- Department
of Applied Chemistry, Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
| | - Tahei Tahara
- Molecular
Spectroscopy Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
- Ultrafast
Spectroscopy Research Team, RIKEN Center
for Advanced Photonics (RAP), Wako, Saitama 351-0198, Japan
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10
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Soltész D, Szabó I, Bánóczi Z. The Balance between Hydrophobicity/Aromaticity and Positively Charged Residues May Influence the Cell Penetration Ability. Pharmaceutics 2023; 15:pharmaceutics15041267. [PMID: 37111751 PMCID: PMC10146604 DOI: 10.3390/pharmaceutics15041267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/05/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
Cell-penetrating peptides (CPPs) are commonly modified to increase their cellular uptake, alter the mechanism of penetration or enhance their endosomal release. Earlier, we described the internalization enhancement ability of the 4-((4-(dimethylamino)phenyl)azo)benzoyl (Dabcyl) group. We proved that this modification on the N-terminus of tetra- and hexaarginine enhanced their cellular uptake. The introduction of an aromatic ring 4-(aminomethyl) benzoic acid, AMBA) into the peptide backbone has a synergistic effect with Dabcyl, and the tetraarginine derivatives had outstanding cellular uptake. Based on these results, the effect of Dabcyl or Dabcyl-AMBA modification on the internalization of oligoarginines was studied. Oligoarginines were modified with these groups and their internalization was measured using flow cytometry. The concentration dependence of the cellular uptake of selected constructs was compared too. Their internalization mechanism was also examined by using different endocytosis inhibitors. While the effect of the Dabcyl group was optimal for hexaarginine, the Dabcyl-AMBA group increased the cellular uptake in the case of all oligoarginines. All derivatives, with the exception of only tetraarginine, were more effective than the octaarginine control. The internalization mechanism was dependent on the size of the oligoarginine and was independent of the modification. Our findings suggest that these modifications enhanced the internalization of oligoarginines and resulted in novel, very effective CPPs.
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Affiliation(s)
- Dóra Soltész
- Department of Organic Chemistry, Eötvös L. University, 1117 Budapest, Hungary
| | - Ildikó Szabó
- ELKH-ELTE Research Group of Peptide Chemistry, 1117 Budapest, Hungary
| | - Zoltán Bánóczi
- Department of Organic Chemistry, Eötvös L. University, 1117 Budapest, Hungary
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11
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Feigenson GW, Enoki TA. Nano-scale domains in the plasma membrane are like macroscopic domains in asymmetric bilayers. Biophys J 2023; 122:925-930. [PMID: 36380589 PMCID: PMC10111217 DOI: 10.1016/j.bpj.2022.11.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/02/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
Unfavorable lipid-lipid pairwise interactions between HiTm and LowTm lipids drive liquid-disordered (Ld) + liquid-ordered (Lo) phase separation. Large size of phase domains is opposed by lipid dipole repulsions, which are more significant compared with the pairwise interactions for naturally abundant LowTm lipids such as palmitoyl oleoyl phosphatidylcholine. During the nano-to-macro domain size transition, no lipid phase transition occurs, and measured properties of Ld + Lo nanodomains are found to be essentially the same as those of macrodomains. Use of macrodomains in mixtures to model cell plasma membranes (PM) is helpful, enabling study by optical microscopy. Use of asymmetric giant unilamellar vesicles to model a PM reveals that ordered phase domains in one leaflet induce ordered domains in an otherwise uniform phase in the apposing leaflet that models a cytoplasmic leaflet. Because macro and nano phase properties are so similar, we conclude that a cell PM that has nano-scale Ld + Lo phase domains in the exoplasmic leaflet is likely to induce nano-scale ordered domains in the cytoplasmic leaflet.
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Affiliation(s)
- Gerald W Feigenson
- Department of Molecular Biology and Genetics, Cornell University - Ithaca, Ithaca, New York.
| | - Thais A Enoki
- Department of Molecular Biology and Genetics, Cornell University - Ithaca, Ithaca, New York
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12
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Rodríguez-Moraga N, Ramos-Martín F, Buchoux S, Rippa S, D'Amelio N, Sarazin C. The effect of rhamnolipids on fungal membrane models as described by their interactions with phospholipids and sterols: An in silico study. Front Chem 2023; 11:1124129. [PMID: 36895318 PMCID: PMC9989204 DOI: 10.3389/fchem.2023.1124129] [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: 12/14/2022] [Accepted: 02/06/2023] [Indexed: 02/23/2023] Open
Abstract
Introduction: Rhamnolipids (RLs) are secondary metabolites naturally produced by bacteria of the genera Pseudomonas and Burkholderia with biosurfactant properties. A specific interest raised from their potential as biocontrol agents for crop culture protection in regard to direct antifungal and elicitor activities. As for other amphiphilic compounds, a direct interaction with membrane lipids has been suggested as the key feature for the perception and subsequent activity of RLs. Methods: Molecular Dynamics (MD) simulations are used in this work to provide an atomistic description of their interactions with different membranous lipids and focusing on their antifungal properties. Results and discussion: Our results suggest the insertion of RLs into the modelled bilayers just below the plane drawn by lipid phosphate groups, a placement that is effective in promoting significant membrane fluidification of the hydrophobic core. This localization is promoted by the formation of ionic bonds between the carboxylate group of RLs and the amino group of the phosphatidylethanolamine (PE) or phosphatidylserine (PS) headgroups. Moreover, RL acyl chains adhere to the ergosterol structure, forming a significantly higher number of van der Waals contact with respect to what is observed for phospholipid acyl chains. All these interactions might be essential for the membranotropic-driven biological actions of RLs.
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Affiliation(s)
- Nely Rodríguez-Moraga
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens, France
| | - Francisco Ramos-Martín
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens, France
| | - Sébastien Buchoux
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens, France
| | - Sonia Rippa
- Unité de Génie Enzymatique et Cellulaire, CNRS UMR 7025, Sorbonne Universités, Université de Technologie de Compiègne, Compiègne, France
| | - Nicola D'Amelio
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens, France
| | - Catherine Sarazin
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens, France
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13
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Kovacs T, Nagy P, Panyi G, Szente L, Varga Z, Zakany F. Cyclodextrins: Only Pharmaceutical Excipients or Full-Fledged Drug Candidates? Pharmaceutics 2022; 14:pharmaceutics14122559. [PMID: 36559052 PMCID: PMC9788615 DOI: 10.3390/pharmaceutics14122559] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/15/2022] [Accepted: 11/18/2022] [Indexed: 11/23/2022] Open
Abstract
Cyclodextrins, representing a versatile family of cyclic oligosaccharides, have extensive pharmaceutical applications due to their unique truncated cone-shaped structure with a hydrophilic outer surface and a hydrophobic cavity, which enables them to form non-covalent host-guest inclusion complexes in pharmaceutical formulations to enhance the solubility, stability and bioavailability of numerous drug molecules. As a result, cyclodextrins are mostly considered as inert carriers during their medical application, while their ability to interact not only with small molecules but also with lipids and proteins is largely neglected. By forming inclusion complexes with cholesterol, cyclodextrins deplete cholesterol from cellular membranes and thereby influence protein function indirectly through alterations in biophysical properties and lateral heterogeneity of bilayers. In this review, we summarize the general chemical principles of direct cyclodextrin-protein interactions and highlight, through relevant examples, how these interactions can modify protein functions in vivo, which, despite their huge potential, have been completely unexploited in therapy so far. Finally, we give a brief overview of disorders such as Niemann-Pick type C disease, atherosclerosis, Alzheimer's and Parkinson's disease, in which cyclodextrins already have or could have the potential to be active therapeutic agents due to their cholesterol-complexing or direct protein-targeting properties.
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Affiliation(s)
- Tamas Kovacs
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Peter Nagy
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Lajos Szente
- CycloLab Cyclodextrin R & D Laboratory Ltd., H-1097 Budapest, Hungary
| | - Zoltan Varga
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Florina Zakany
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
- Correspondence:
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14
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Utesch T, Staffa J, Katz S, Yao G, Kozuch J, Hildebrandt P. Potential Distribution across Model Membranes. J Phys Chem B 2022; 126:7664-7675. [PMID: 36137267 DOI: 10.1021/acs.jpcb.2c05372] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Membrane models assembled on electrodes are widely used tools to study potential-dependent molecular processes at or in membranes. However, the relationship between the electrode potential and the potential across the membrane is not known. Here we studied lipid bilayers immobilized on mixed self-assembled monolayers (SAM) on Au electrodes. The mixed SAM was composed of thiol derivatives of different chain lengths such that between the islands of the short one, mercaptobenzonitrile (MBN), and the tethered lipid bilayer an aqueous compartment was formed. The nitrile function of MBN, which served as a reporter group for the vibrational Stark effect (VSE), was probed by surface-enhanced infrared absorption spectroscopy to determine the local electric field as a function of the electrode potential for pure MBN, mixed SAM, and the bilayer system. In parallel, we calculated electric fields at the VSE probe by molecular dynamics (MD) simulations for different charge densities on the metal, thereby mimicking electrode potential changes. The agreement with the experiments was very good for the calculations of the pure MBN SAM and only slightly worse for the mixed SAM. The comparison with the experiments also guided the design of the bilayer system in the MD setups, which were selected to calculate the electrode potential dependence of the transmembrane potential, a quantity that is not directly accessible by the experiments. The results agree very well with estimates in previous studies and thus demonstrate that the present combined experimental-theoretical approach is a promising tool for describing potential-dependent processes at biomimetic interfaces.
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Affiliation(s)
- Tillmann Utesch
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Strasse 10, D-13125 Berlin, Germany
| | - Jana Staffa
- Institut für Chemie, Technische Universität Berlin, Sekr. PC14, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Sagie Katz
- Institut für Chemie, Technische Universität Berlin, Sekr. PC14, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Guiyang Yao
- Institut für Chemie, Technische Universität Berlin, Sekr. PC14, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Jacek Kozuch
- Fachbereich Physik, Experimentelle Molekulare Biophysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.,Forschungsbau SupraFAB, Altensteinstr. 23a, D-14195 Berlin, Germany
| | - Peter Hildebrandt
- Institut für Chemie, Technische Universität Berlin, Sekr. PC14, Straße des 17. Juni 135, D-10623 Berlin, Germany
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15
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Ramos-Martín F, D'Amelio N. Biomembrane lipids: When physics and chemistry join to shape biological activity. Biochimie 2022; 203:118-138. [PMID: 35926681 DOI: 10.1016/j.biochi.2022.07.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/13/2022] [Accepted: 07/21/2022] [Indexed: 11/02/2022]
Abstract
Biomembranes constitute the first lines of defense of cells. While small molecules can often permeate cell walls in bacteria and plants, they are generally unable to penetrate the barrier constituted by the double layer of phospholipids, unless specific receptors or channels are present. Antimicrobial or cell-penetrating peptides are in fact highly specialized molecules able to bypass this barrier and even discriminate among different cell types. This capacity is made possible by the intrinsic properties of its phospholipids, their distribution between the internal and external leaflet, and their ability to mutually interact, modulating the membrane fluidity and the exposition of key headgroups. Although common phospholipids can be found in the membranes of most organisms, some are characteristic of specific cell types. Here, we review the properties of the most common lipids and describe how they interact with each other in biomembrane. We then discuss how their assembly in bilayers determines some key physical-chemical properties such as permeability, potential and phase status. Finally, we describe how the exposition of specific phospholipids determines the recognition of cell types by membrane-targeting molecules.
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Affiliation(s)
- Francisco Ramos-Martín
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens, 80039, France.
| | - Nicola D'Amelio
- Unité de Génie Enzymatique et Cellulaire UMR 7025 CNRS, Université de Picardie Jules Verne, Amiens, 80039, France.
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16
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Mitchell W, Tamucci JD, Ng EL, Liu S, Birk AV, Szeto HH, May ER, Alexandrescu AT, Alder NN. Structure-activity relationships of mitochondria-targeted tetrapeptide pharmacological compounds. eLife 2022; 11:75531. [PMID: 35913044 PMCID: PMC9342957 DOI: 10.7554/elife.75531] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 07/03/2022] [Indexed: 11/13/2022] Open
Abstract
Mitochondria play a central role in metabolic homeostasis, and dysfunction of this organelle underpins the etiology of many heritable and aging-related diseases. Tetrapeptides with alternating cationic and aromatic residues such as SS-31 (elamipretide) show promise as therapeutic compounds for mitochondrial disorders. In this study, we conducted a quantitative structure-activity analysis of three alternative tetrapeptide analogs, benchmarked against SS-31, that differ with respect to aromatic side chain composition and sequence register. We present the first structural models for this class of compounds, obtained with Nuclear Magnetic Resonance (NMR) and molecular dynamics approaches, showing that all analogs except for SS-31 form compact reverse turn conformations in the membrane-bound state. All peptide analogs bound cardiolipin-containing membranes, yet they had significant differences in equilibrium binding behavior and membrane interactions. Notably, analogs had markedly different effects on membrane surface charge, supporting a mechanism in which modulation of membrane electrostatics is a key feature of their mechanism of action. The peptides had no strict requirement for side chain composition or sequence register to permeate cells and target mitochondria in mammalian cell culture assays. All four peptides were pharmacologically active in serum withdrawal cell stress models yet showed significant differences in their abilities to restore mitochondrial membrane potential, preserve ATP content, and promote cell survival. Within our peptide set, the analog containing tryptophan side chains, SPN10, had the strongest impact on most membrane properties and showed greatest efficacy in cell culture studies. Taken together, these results show that side chain composition and register influence the activity of these mitochondria-targeted peptides, helping provide a framework for the rational design of next-generation therapeutics with enhanced potency.
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Affiliation(s)
- Wayne Mitchell
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Jeffrey D Tamucci
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Emery L Ng
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Shaoyi Liu
- Social Profit Network, Menlo Park, CA, United States
| | - Alexander V Birk
- Department of Biology, York College of CUNY, New York, NY, United States
| | - Hazel H Szeto
- Social Profit Network, Menlo Park, CA, United States
| | - Eric R May
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Andrei T Alexandrescu
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Nathan N Alder
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
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17
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Sharma GP, Meyer AC, Habeeb S, Karbach M, Müller G. Free-energy landscapes and insertion pathways for peptides in membrane environment. Phys Rev E 2022; 106:014404. [PMID: 35974613 DOI: 10.1103/physreve.106.014404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
Free-energy landscapes for short peptides-specifically for variants of the pH low insertion peptide (pHLIP)-in the heterogeneous environment of a lipid bilayer or cell membrane are constructed, taking into account a set of dominant interactions and the conformational preferences of the peptide backbone. Our methodology interprets broken internal H-bonds along the backbone of a polypeptide as statistically interacting quasiparticles, activated from the helix reference state. The favored conformation depends on the local environment (ranging from polar to nonpolar), specifically on the availability of external H-bonds (with H_{2}O molecules or lipid headgroups) to replace internal H-bonds. The dominant side-chain contribution is accounted for by residue-specific transfer free energies between polar and nonpolar environments. The free-energy landscape is sensitive to the level of pH in the aqueous environment surrounding the membrane. For high pH, we identify pathways of descending free energy that suggest a coexistence of membrane-adsorbed peptides with peptides in solution. A drop in pH raises the degree of protonation of negatively charged residues and thus increases the hydrophobicity of peptide segments near the C terminus. For low pH, we identify insertion pathways between the membrane-adsorbed state and a stable trans-membrane state with the C terminus having crossed the membrane.
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Affiliation(s)
- Ganga P Sharma
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, USA
| | - Aaron C Meyer
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, USA
| | - Suhail Habeeb
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, USA
| | - Michael Karbach
- Fachgruppe Physik, Bergische Universität Wuppertal, D-42097 Wuppertal, Germany
| | - Gerhard Müller
- Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, USA
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18
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Sarkar P, Chattopadhyay A. Membrane Dipole Potential: An Emerging Approach to Explore Membrane Organization and Function. J Phys Chem B 2022; 126:4415-4430. [PMID: 35696090 DOI: 10.1021/acs.jpcb.2c02476] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Biological membranes are complex organized molecular assemblies of lipids and proteins that provide cells and membrane-bound intracellular organelles their individual identities by morphological compartmentalization. Membrane dipole potential originates from the electrostatic potential difference within the membrane due to the nonrandom arrangement (orientation) of amphiphile and solvent (water) dipoles at the membrane interface. In this Feature Article, we will focus on the measurement of dipole potential using electrochromic fluorescent probes and highlight interesting applications. In addition, we will focus on ratiometric fluorescence microscopic imaging technique to measure dipole potential in cellular membranes, a technique that can be used to address novel problems in cell biology which are otherwise difficult to address using available approaches. We envision that membrane dipole potential could turn out to be a convenient tool in exploring the complex interplay between membrane lipids and proteins and could provide novel insights in membrane organization and function.
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Affiliation(s)
- Parijat Sarkar
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
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19
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Yudovich S, Marzouqe A, Kantorovitsch J, Teblum E, Chen T, Enderlein J, Miller EW, Weiss S. Electrically Controlling and Optically Observing the Membrane Potential of Supported Lipid Bilayers. Biophys J 2022; 121:2624-2637. [PMID: 35619563 DOI: 10.1016/j.bpj.2022.05.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 04/26/2022] [Accepted: 05/23/2022] [Indexed: 11/02/2022] Open
Abstract
Supported lipid bilayers are a well-developed model system for the study of membranes and their associated proteins, such as membrane channels, enzymes, and receptors. These versatile model membranes can be made from various components, ranging from simple synthetic phospholipids to complex mixtures of constituents, mimicking the cell membrane with its relevant physiochemical and molecular phenomena. In addition, the high stability of supported lipid bilayers allows for their study via a wide array of experimental probes. In this work, we describe a platform for supported lipid bilayers that is accessible both electrically and optically, and demonstrate direct optical observation of the transmembrane potential of supported lipid bilayers. We show that the polarization of the supported membrane can be electrically controlled and optically probed using voltage-sensitive dyes. Membrane polarization dynamics is understood through electrochemical impedance spectroscopy and the analysis of an equivalent electrical circuit model. In addition, we describe the effect of the conducting electrode layer on the fluorescence of the optical probe through metal-induced energy transfer, and show that while this energy transfer has an adverse effect on the voltage sensitivity of the fluorescent probe, its strong distance dependency allows for axial localization of fluorescent emitters with ultrahigh accuracy. We conclude with a discussion on possible applications of this platform for the study of voltage-dependent membrane proteins and other processes in membrane biology and surface science.
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Affiliation(s)
- Shimon Yudovich
- Department of Physics, Bar-Ilan University, Ramat-Gan, 52900, Israel; Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan, 52900, Israel.
| | - Adan Marzouqe
- Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan, 52900, Israel; Department of Chemistry, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Joseph Kantorovitsch
- Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Eti Teblum
- Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Tao Chen
- Third Institute of Physics-Biophysics, Georg August University, 37077 Göttingen, Germany
| | - Jörg Enderlein
- Third Institute of Physics-Biophysics, Georg August University, 37077 Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), Georg August University, Germany
| | - Evan W Miller
- Departments of Chemistry, Molecular & Cell Biology, and Helen Wills Neuroscience Institute, University of California, Berkeley, California 94720, United States
| | - Shimon Weiss
- Department of Physics, Bar-Ilan University, Ramat-Gan, 52900, Israel; Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan, 52900, Israel; Departments of Chemistry and Biochemistry, Physiology, and California NanoSystems Institute, University of California Los Angeles, Los Angeles, CA 90095.
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20
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Effect of Local Anesthetics on Dipole Potential of Different Phase Membranes: A Fluorescence Study. J Membr Biol 2022; 255:363-369. [PMID: 35587273 DOI: 10.1007/s00232-022-00240-2] [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: 03/15/2022] [Accepted: 04/22/2022] [Indexed: 12/17/2022]
Abstract
The molecular mechanism behind the action of local anesthetics is not well understood. Phenylethanol (PEtOH) is an ingredient of essential oils with a rose-like odor, and it has previously been used as a local anesthetic. In this work, we explored the effect of PEtOH on dipole potential in membranes representing biologically relevant phases, employing the dual-wavelength ratiometric method utilizing the potential-sensitive probe di-8-ANEPPS. Our results show that PEtOH reduces membrane dipole potential in membranes of all biologically relevant phases (gel, liquid-ordered, and fluid) in a concentration-dependent manner. To the best of our knowledge, these results constitute one of the early reports describing reduction of membrane dipole potential induced by local anesthetics, irrespective of membrane phase.
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21
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Nonlinear electric response of the diffuse double layer to an abrupt charge displacement inside a biological membrane. Bioelectrochemistry 2022; 146:108138. [DOI: 10.1016/j.bioelechem.2022.108138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 04/15/2022] [Accepted: 04/20/2022] [Indexed: 12/18/2022]
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22
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Noble BB, Todorova N, Yarovsky I. Electromagnetic bioeffects: a multiscale molecular simulation perspective. Phys Chem Chem Phys 2022; 24:6327-6348. [PMID: 35245928 DOI: 10.1039/d1cp05510k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Electromagnetic bioeffects remain an enigma from both the experimental and theoretical perspectives despite the ubiquitous presence of related technologies in contemporary life. Multiscale computational modelling can provide valuable insights into biochemical systems and predict how they will be perturbed by external stimuli. At a microscopic level, it can be used to determine what (sub)molecular scale reactions various stimuli might induce; at a macroscopic level, it can be used to examine how these changes affect dynamic behaviour of essential molecules within the crowded biomolecular milieu in living tissues. In this review, we summarise and evaluate recent computational studies that examined the impact of externally applied electric and electromagnetic fields on biologically relevant molecular systems. First, we briefly outline the various methodological approaches that have been employed to study static and oscillating field effects across different time and length scales. The practical value of such modelling is then illustrated through representative case-studies that showcase the diverse effects of electric and electromagnetic field on the main physiological solvent - water, and the essential biomolecules - DNA, proteins, lipids, as well as some novel biomedically relevant nanomaterials. The implications and relevance of the theoretical multiscale modelling to practical applications in therapeutic medicine are also discussed. Finally, we summarise ongoing challenges and potential opportunities for theoretical modelling to advance the current understanding of electromagnetic bioeffects for their modulation and/or beneficial exploitation in biomedicine and industry.
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Affiliation(s)
- Benjamin B Noble
- School of Engineering, RMIT University, GPO Box 2476, Melbourne, Australia. .,Australian Centre for Electromagnetic Bioeffects Research, Australia
| | - Nevena Todorova
- School of Engineering, RMIT University, GPO Box 2476, Melbourne, Australia. .,Australian Centre for Electromagnetic Bioeffects Research, Australia
| | - Irene Yarovsky
- School of Engineering, RMIT University, GPO Box 2476, Melbourne, Australia. .,Australian Centre for Electromagnetic Bioeffects Research, Australia
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23
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It Takes More than Two to Tango: Complex, Hierarchal, and Membrane-Modulated Interactions in the Regulation of Receptor Tyrosine Kinases. Cancers (Basel) 2022; 14:cancers14040944. [PMID: 35205690 PMCID: PMC8869822 DOI: 10.3390/cancers14040944] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/09/2022] [Accepted: 02/12/2022] [Indexed: 12/18/2022] Open
Abstract
The search for an understanding of how cell fate and motility are regulated is not a purely scientific undertaking, but it can also lead to rationally designed therapies against cancer. The discovery of tyrosine kinases about half a century ago, the subsequent characterization of certain transmembrane receptors harboring tyrosine kinase activity, and their connection to the development of human cancer ushered in a new age with the hope of finding a treatment for malignant diseases in the foreseeable future. However, painstaking efforts were required to uncover the principles of how these receptors with intrinsic tyrosine kinase activity are regulated. Developments in molecular and structural biology and biophysical approaches paved the way towards better understanding of these pathways. Discoveries in the past twenty years first resulted in the formulation of textbook dogmas, such as dimerization-driven receptor association, which were followed by fine-tuning the model. In this review, the role of molecular interactions taking place during the activation of receptor tyrosine kinases, with special attention to the epidermal growth factor receptor family, will be discussed. The fact that these receptors are anchored in the membrane provides ample opportunities for modulatory lipid-protein interactions that will be considered in detail in the second part of the manuscript. Although qualitative and quantitative alterations in lipids in cancer are not sufficient in their own right to drive the malignant transformation, they both contribute to tumor formation and also provide ways to treat cancer. The review will be concluded with a summary of these medical aspects of lipid-protein interactions.
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24
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Chan SSY, Lee D, Meivita MP, Li L, Tan YS, Bajalovic N, Loke DK. Ultrasensitive two-dimensional material-based MCF-7 cancer cell sensor driven by perturbation processes. NANOSCALE ADVANCES 2021; 3:6974-6983. [PMID: 36132361 PMCID: PMC9419592 DOI: 10.1039/d1na00614b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/13/2021] [Indexed: 06/15/2023]
Abstract
Changes in lipid composition and structure during cell development can be markers for cell apoptosis or various diseases such as cancer. Although traditional fluorescence techniques utilising molecular probes have been studied, these methods are limited in studying these micro-changes as they require complex probe preparation and cannot be reused, making cell monitoring and detection challenging. Here, we developed a direct current (DC) resistance sensor based on two-dimensional (2D) molybdenum disulfide (MoS2) nanosheets to enable cancer cell-specific detection dependent on micro-changes in the cancer cell membrane. Atomistic molecular dynamics (MD) simulations were used to study the interaction between 2D MoS2 and cancer lipid bilayer systems, and revealed that previously unconsidered perturbations in the lipid bilayer can cause an increase in resistance. Under an applied DC sweep, we observed an increase in resistance when cancer cells were incubated with the nanosheets. Furthermore, a correlation was observed between the resistance and breast cancer epithelial cell (MCF-7) population, illustrating a cell population-dependent sensitivity of our method. Our method has a detection limit of ∼3 × 103 cells, below a baseline of ∼1 × 104 cells for the current state-of-the-art electrical-based biosensors using an adherent monolayer with homogenous cells. This combination of a unique 2D material and electrical resistance framework represents a promising approach for the early detection of cancerous cells and to reduce the risk of post-surgery cancer recurrence.
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Affiliation(s)
- Sophia S Y Chan
- Department of Science, Mathematics and Technology, Singapore University of Technology and Design Singapore 487372 Singapore
| | - Denise Lee
- Department of Science, Mathematics and Technology, Singapore University of Technology and Design Singapore 487372 Singapore
| | - Maria Prisca Meivita
- Department of Science, Mathematics and Technology, Singapore University of Technology and Design Singapore 487372 Singapore
| | - Lunna Li
- Department of Science, Mathematics and Technology, Singapore University of Technology and Design Singapore 487372 Singapore
| | - Yaw Sing Tan
- Bioinformatics Institute, Agency for Science, Technology and Research (ASTAR) Singapore 138671 Singapore
| | - Natasa Bajalovic
- Department of Science, Mathematics and Technology, Singapore University of Technology and Design Singapore 487372 Singapore
| | - Desmond K Loke
- Department of Science, Mathematics and Technology, Singapore University of Technology and Design Singapore 487372 Singapore
- Office of Innovation, Changi General Hospital Singapore 529889 Singapore
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25
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Zakharova AA, Efimova SS, Ostroumova OS. Phosphodiesterase Type 5 Inhibitors Greatly Affect Physicochemical Properties of Model Lipid Membranes. MEMBRANES 2021; 11:membranes11110893. [PMID: 34832122 PMCID: PMC8622654 DOI: 10.3390/membranes11110893] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/17/2021] [Accepted: 11/17/2021] [Indexed: 01/04/2023]
Abstract
Although phosphodiesterase type 5 inhibitors are widely used and well-studied drugs, the potential benefits of their application in the treatment of various diseases and new drug delivery systems, including liposome forms, are still being discussed. In this regard, the role of the lipid matrix of cell membranes in the pharmacological action of the inhibitors is of special interest. It was shown that sildenafil, vardenafil, and tadalafil caused a significant decrease in the boundary potential of model membranes composed of palmitoyloleoylphosphatidylcholine or its mixture with cholesterol, by 70–80 mV. The reduction in the membrane dipole potential induced by inhibitors led to a 20–25% increase in the conductance of cation-selective pores formed by the antimicrobial peptide gramicidin A. The addition of sildenafil or vardenafil also led to a significant decrease in the temperature of the main phase transition of dipalmytoylphosphatidylcholine, by about 1.5 °C, while tadalafil did not change the melting temperature. Sildenafil, vardenafil, and tadalafil enhanced the pore-forming activity of the antifungal polyene antibiotic nystatin by 11, 13, and 2 times, respectively. This fact might indicate the induction of membrane curvature stress by the inhibitors. The data obtained might be of special interest for the development of lipid-mediated forms of drugs.
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26
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Vitkova V, Yordanova V, Staneva G, Petkov O, Stoyanova-Ivanova A, Antonova K, Popkirov G. Dielectric Properties of Phosphatidylcholine Membranes and the Effect of Sugars. MEMBRANES 2021; 11:membranes11110847. [PMID: 34832076 PMCID: PMC8623822 DOI: 10.3390/membranes11110847] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/25/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022]
Abstract
Simple carbohydrates are associated with the enhanced risk of cardiovascular disease and adverse changes in lipoproteins in the organism. Conversely, sugars are known to exert a stabilizing effect on biological membranes, and this effect is widely exploited in medicine and industry for cryopreservation of tissues and materials. In view of elucidating molecular mechanisms involved in the interaction of mono- and disaccharides with biomimetic lipid systems, we study the alteration of dielectric properties, the degree of hydration, and the rotational order parameter and dipole potential of lipid bilayers in the presence of sugars. Frequency-dependent deformation of cell-size unilamellar lipid vesicles in alternating electric fields and fast Fourier transform electrochemical impedance spectroscopy are applied to measure the specific capacitance of phosphatidylcholine lipid bilayers in sucrose, glucose and fructose aqueous solutions. Alteration of membrane specific capacitance is reported in sucrose solutions, while preservation of membrane dielectric properties is established in the presence of glucose and fructose. We address the effect of sugars on the hydration and the rotational order parameter for 1-palmitoyl-2-oleoyl-sn-glycero-3- phosphocholine (POPC) and 1-stearoyl-2-oleoyl-sn-glycero-3- phosphocholine (SOPC). An increased degree of lipid packing is reported in sucrose solutions. The obtained results provide evidence that some small carbohydrates are able to change membrane dielectric properties, structure, and order related to membrane homeostasis. The reported data are also relevant to future developments based on the response of lipid bilayers to external physical stimuli such as electric fields and temperature changes.
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Affiliation(s)
- Victoria Vitkova
- Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee, Blvd., 1784 Sofia, Bulgaria; (O.P.); (A.S.-I.); (K.A.)
- Correspondence:
| | - Vesela Yordanova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria; (V.Y.); (G.S.)
| | - Galya Staneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria; (V.Y.); (G.S.)
| | - Ognyan Petkov
- Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee, Blvd., 1784 Sofia, Bulgaria; (O.P.); (A.S.-I.); (K.A.)
| | - Angelina Stoyanova-Ivanova
- Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee, Blvd., 1784 Sofia, Bulgaria; (O.P.); (A.S.-I.); (K.A.)
| | - Krassimira Antonova
- Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee, Blvd., 1784 Sofia, Bulgaria; (O.P.); (A.S.-I.); (K.A.)
| | - Georgi Popkirov
- Central Laboratory of Solar Energy and New Energy Sources, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee, Blvd., 1784 Sofia, Bulgaria;
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27
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Asandei A, Mereuta L, Schiopu I, Park Y, Luchian T. Teaching an old dog new tricks: A lipid membrane-based electric immunosensor for real-time probing of the spike S 1 protein subunit from SARS-CoV-2. Proteomics 2021; 22:e2100047. [PMID: 34586750 PMCID: PMC8646443 DOI: 10.1002/pmic.202100047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/09/2021] [Accepted: 09/24/2021] [Indexed: 11/29/2022]
Abstract
Fast, cheap, and easy to implement point‐of‐care testing for various pathogens constituted a game changer in past years due to its potential for early disease diagnosis. Herein, we report on the proof‐of‐concept of a simple method enabling in vitro detection of a structural spike protein subunit from the SARS‐CoV‐2 (S1) in aqueous samples. At the core of this discovery lies the well‐known paradigm of monitoring the capacitive current across a reconstituted zwitterionic lipid membrane subjected to a periodic transmembrane potential, followed by the real‐time spectral analysis enabling the extraction of the second harmonic of the capacitive current. Subsequent changes in the amplitude of this harmonic recorded during lipid membrane–S1 interactions were correlated with alterations induced in the inner membrane potential profile by the S1 protein subunit adsorption, and were shown to be augmented by ionic strength, the presence of a specific monoclonal antibody designed against the S1 subunit and the angiotensin‐converting enzyme 2 (ACE2) protein receptor, and uninhibited by the presence of other human serum proteins.
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Affiliation(s)
- Alina Asandei
- Sciences Department, Interdisciplinary Research Institute, Alexandru I. Cuza University, Iasi, Romania
| | - Loredana Mereuta
- Department of Physics, Alexandru I. Cuza University, Iasi, Romania
| | - Irina Schiopu
- Sciences Department, Interdisciplinary Research Institute, Alexandru I. Cuza University, Iasi, Romania
| | - Yoonkyung Park
- Department of Biomedical Science and Research Center for Proteinaceous Materials (RCPM), Chosun University, Gwangju, Republic of Korea
| | - Tudor Luchian
- Department of Physics, Alexandru I. Cuza University, Iasi, Romania
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28
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Abstract
The ubiquity of aqueous solutions in contact with charged surfaces and the realization that the molecular-level details of water-surface interactions often determine interfacial functions and properties relevant in many natural processes have led to intensive research. Even so, many open questions remain regarding the molecular picture of the interfacial organization and preferential alignment of water molecules, as well as the structure of water molecules and ion distributions at different charged interfaces. While water, solutes and charge are present in each of these systems, the substrate can range from living tissues to metals. This diversity in substrates has led to different communities considering each of these types of aqueous interface. In this Review, by considering water in contact with metals, oxides and biomembranes, we show the essential similarity of these disparate systems. While in each case the classical mean-field theories can explain many macroscopic and mesoscopic observations, it soon becomes apparent that such theories fail to explain phenomena for which molecular properties are relevant, such as interfacial chemical conversion. We highlight the current knowledge and limitations in our understanding and end with a view towards future opportunities in the field.
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29
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Batta G, Kárpáti L, Henrique GF, Tóth G, Tarapcsák S, Kovacs T, Zakany F, Mándity IM, Nagy P. Statin-boosted cellular uptake and endosomal escape of penetratin due to reduced membrane dipole potential. Br J Pharmacol 2021; 178:3667-3681. [PMID: 33908640 DOI: 10.1111/bph.15509] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 04/19/2021] [Accepted: 04/23/2021] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND AND PURPOSE Cell penetrating peptides are promising tools for delivery of cargo into cells, but factors limiting or facilitating their cellular uptake are largely unknown. We set out to study the effect of the biophysical properties of the cell membrane on the uptake of penetratin, a cell penetrating peptide. EXPERIMENTAL APPROACH Using labelling with pH-insensitive and pH-sensitive dyes, the kinetics of cellular uptake and endo-lysosomal escape of penetratin were studied by flow cytometry. KEY RESULTS We report that escape of penetratin from acidic endo-lysosomal compartments is retarded compared with its total cellular uptake. The membrane dipole potential, known to alter transmembrane transport of charged molecules, is shown to be negatively correlated with the concentration of penetratin in the cytoplasmic compartment. Treatment of cells with therapeutically relevant concentrations of atorvastatin, an inhibitor of HMG-CoA reductase and cholesterol synthesis, significantly increased endosomal escape of penetratin in two different cell types. This effect of atorvastatin correlated with its ability to decrease the membrane dipole potential. CONCLUSION AND IMPLICATIONS These results highlight the importance of the dipole potential in regulating cellular uptake of cell penetrating peptides and suggest a clinically relevant way of boosting this process.
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Affiliation(s)
- Gyula Batta
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Levente Kárpáti
- Department of Organic Chemistry, Faculty of Pharmacy, Semmelweis University, Budapest, Hungary.,TTK Lendület Artificial Transporter Research Group, Institute of Materials and Environmental Chemistry, Research Center for Natural Sciences, Budapest, Hungary
| | - Gabriela Fulaneto Henrique
- Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Gabriella Tóth
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Szabolcs Tarapcsák
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Utah Center for Genetic Discovery, Eccles Institute of Human Genetics, University of Utah, Salt Lake City, Utah, USA
| | - Tamas Kovacs
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Florina Zakany
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - István M Mándity
- Department of Organic Chemistry, Faculty of Pharmacy, Semmelweis University, Budapest, Hungary.,TTK Lendület Artificial Transporter Research Group, Institute of Materials and Environmental Chemistry, Research Center for Natural Sciences, Budapest, Hungary
| | - Peter Nagy
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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30
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Kostritskii AY, Alleva C, Cönen S, Machtens JP. g_elpot: A Tool for Quantifying Biomolecular Electrostatics from Molecular Dynamics Trajectories. J Chem Theory Comput 2021; 17:3157-3167. [PMID: 33914551 DOI: 10.1021/acs.jctc.0c01246] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Electrostatic forces drive a wide variety of biomolecular processes by defining the energetics of the interaction between biomolecules and charged substances. Molecular dynamics (MD) simulations provide trajectories that contain ensembles of structural configurations sampled by biomolecules and their environment. Although this information can be used for high-resolution characterization of biomolecular electrostatics, it has not yet been possible to calculate electrostatic potentials from MD trajectories in a way allowing for quantitative connection to energetics. Here, we present g_elpot, a GROMACS-based tool that utilizes the smooth particle mesh Ewald method to quantify the electrostatics of biomolecules by calculating potential within water molecules that are explicitly present in biomolecular MD simulations. g_elpot can extract the global distribution of the electrostatic potential from MD trajectories and measure its time course in functionally important regions of a biomolecule. To demonstrate that g_elpot can be used to gain biophysical insights into various biomolecular processes, we applied the tool to MD trajectories of the P2X3 receptor, TMEM16 lipid scramblases, the secondary-active transporter GltPh, and DNA complexed with cationic polymers. Our results indicate that g_elpot is well suited for quantifying electrostatics in biomolecular systems to provide a deeper understanding of its role in biomolecular processes.
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Affiliation(s)
- Andrei Y Kostritskii
- Institute of Biological Information Processing (IBI-1), Molekular- und Zellphysiologie, and JARA-HPC, Forschungszentrum Jülich, 52425 Jülich, Germany.,Department of Physics, RWTH Aachen University, 52062 Aachen, Germany.,Institute of Clinical Pharmacology, RWTH Aachen University, 52062 Aachen, Germany
| | - Claudia Alleva
- Institute of Biological Information Processing (IBI-1), Molekular- und Zellphysiologie, and JARA-HPC, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Saskia Cönen
- Institute of Biological Information Processing (IBI-1), Molekular- und Zellphysiologie, and JARA-HPC, Forschungszentrum Jülich, 52425 Jülich, Germany.,Institute of Clinical Pharmacology, RWTH Aachen University, 52062 Aachen, Germany
| | - Jan-Philipp Machtens
- Institute of Biological Information Processing (IBI-1), Molekular- und Zellphysiologie, and JARA-HPC, Forschungszentrum Jülich, 52425 Jülich, Germany.,Institute of Clinical Pharmacology, RWTH Aachen University, 52062 Aachen, Germany
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31
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El-Beyrouthy J, Freeman E. Characterizing the Structure and Interactions of Model Lipid Membranes Using Electrophysiology. MEMBRANES 2021; 11:319. [PMID: 33925756 PMCID: PMC8145864 DOI: 10.3390/membranes11050319] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/22/2021] [Accepted: 04/25/2021] [Indexed: 11/16/2022]
Abstract
The cell membrane is a protective barrier whose configuration determines the exchange both between intracellular and extracellular regions and within the cell itself. Consequently, characterizing membrane properties and interactions is essential for advancements in topics such as limiting nanoparticle cytotoxicity. Characterization is often accomplished by recreating model membranes that approximate the structure of cellular membranes in a controlled environment, formed using self-assembly principles. The selected method for membrane creation influences the properties of the membrane assembly, including their response to electric fields used for characterizing transmembrane exchanges. When these self-assembled model membranes are combined with electrophysiology, it is possible to exploit their non-physiological mechanics to enable additional measurements of membrane interactions and phenomena. This review describes several common model membranes including liposomes, pore-spanning membranes, solid supported membranes, and emulsion-based membranes, emphasizing their varying structure due to the selected mode of production. Next, electrophysiology techniques that exploit these structures are discussed, including conductance measurements, electrowetting and electrocompression analysis, and electroimpedance spectroscopy. The focus of this review is linking each membrane assembly technique to the properties of the resulting membrane, discussing how these properties enable alternative electrophysiological approaches to measuring membrane characteristics and interactions.
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Affiliation(s)
| | - Eric Freeman
- School of Environmental, Civil, Agricultural and Mechanical Engineering, College of Engineering, University of Georgia, Athens, GA 30602, USA;
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32
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Zakany F, Szabo M, Batta G, Kárpáti L, Mándity IM, Fülöp P, Varga Z, Panyi G, Nagy P, Kovacs T. An ω-3, but Not an ω-6 Polyunsaturated Fatty Acid Decreases Membrane Dipole Potential and Stimulates Endo-Lysosomal Escape of Penetratin. Front Cell Dev Biol 2021; 9:647300. [PMID: 33912562 PMCID: PMC8074792 DOI: 10.3389/fcell.2021.647300] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 03/22/2021] [Indexed: 12/21/2022] Open
Abstract
Although the largely positive intramembrane dipole potential (DP) may substantially influence the function of transmembrane proteins, its investigation is deeply hampered by the lack of measurement techniques suitable for high-throughput examination of living cells. Here, we describe a novel emission ratiometric flow cytometry method based on F66, a 3-hydroxiflavon derivative, and demonstrate that 6-ketocholestanol, cholesterol and 7-dehydrocholesterol, saturated stearic acid (SA) and ω-6 γ-linolenic acid (GLA) increase, while ω-3 α-linolenic acid (ALA) decreases the DP. These changes do not correlate with alterations in cell viability or membrane fluidity. Pretreatment with ALA counteracts, while SA or GLA enhances cholesterol-induced DP elevations. Furthermore, ALA (but not SA or GLA) increases endo-lysosomal escape of penetratin, a cell-penetrating peptide. In summary, we have developed a novel method to measure DP in large quantities of individual living cells and propose ALA as a physiological DP lowering agent facilitating cytoplasmic entry of penetratin.
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Affiliation(s)
- Florina Zakany
- Division of Biophysics, Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Mate Szabo
- Division of Biophysics, Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gyula Batta
- Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Levente Kárpáti
- Department of Organic Chemistry, Faculty of Pharmacy, Semmelweis University, Budapest, Hungary
| | - István M. Mándity
- Department of Organic Chemistry, Faculty of Pharmacy, Semmelweis University, Budapest, Hungary
- Lendület-Artificial Chloride Ion Transporter Group, Institute of Materials and Environmental Chemistry, Research Center for Natural Sciences, Budapest, Hungary
| | - Péter Fülöp
- Division of Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zoltan Varga
- Division of Biophysics, Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gyorgy Panyi
- Division of Biophysics, Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Peter Nagy
- Division of Biophysics, Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamas Kovacs
- Division of Biophysics, Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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33
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Gaddale Devanna KK, Gawel JM, Prime TA, Cvetko F, Benincá C, Caldwell ST, Negoda A, Harrison A, James AM, Pavlov EV, Murphy MP, Hartley RC. Tetra-arylborate lipophilic anions as targeting groups. Chem Commun (Camb) 2021; 57:3147-3150. [PMID: 33634803 PMCID: PMC8062962 DOI: 10.1039/d0cc07924c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/16/2021] [Indexed: 11/21/2022]
Abstract
Tetraphenylborate (TPB) anions traverse membranes but are excluded from mitochondria by the membrane potential (Δψ). TPB-conjugates also distributed across membranes in response to Δψ, but surprisingly, they rapidly entered cells. They accumulated within lysosomes following endocystosis. This pH-independent targeting of lysosomes makes possible new classes of probe and bioactive molecules.
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Affiliation(s)
| | - Justyna M. Gawel
- School of Chemistry
, University of Glasgow
,
Glasgow
, G12 8QQ
, UK
.
| | - Tracy A. Prime
- MRC Mitochondrial Biology Unit
, Hills Road
, University of Cambridge
,
CB2 0XY
, UK
.
| | - Filip Cvetko
- MRC Mitochondrial Biology Unit
, Hills Road
, University of Cambridge
,
CB2 0XY
, UK
.
| | - Cristiane Benincá
- MRC Mitochondrial Biology Unit
, Hills Road
, University of Cambridge
,
CB2 0XY
, UK
.
| | | | - Alexander Negoda
- Department of Physiology and Biophysics
, Dalhousie University
,
Halifax
, Nova Scotia
, Canada
| | - Andrew Harrison
- MRC Mitochondrial Biology Unit
, Hills Road
, University of Cambridge
,
CB2 0XY
, UK
.
| | - Andrew M. James
- MRC Mitochondrial Biology Unit
, Hills Road
, University of Cambridge
,
CB2 0XY
, UK
.
| | - Evgeny V. Pavlov
- New York University
, College of Dentistry
, Department of Molecular Pathobiology
, 345 East 24th Street
,
New York
, NY 10010
, USA
| | - Michael P. Murphy
- MRC Mitochondrial Biology Unit
, Hills Road
, University of Cambridge
,
CB2 0XY
, UK
.
- Department of Medicine
, University of Cambridge
,
Cambridge
, UK
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34
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Gheorghiu A, Coveney PV, Arabi AA. The influence of external electric fields on proton transfer tautomerism in the guanine-cytosine base pair. Phys Chem Chem Phys 2021; 23:6252-6265. [PMID: 33735350 PMCID: PMC8330266 DOI: 10.1039/d0cp06218a] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/23/2021] [Indexed: 12/28/2022]
Abstract
The Watson-Crick base pair proton transfer tautomers would be widely considered as a source of spontaneous mutations in DNA replication if not for their short lifetimes and thermodynamic instability. This work investigates the effects external electric fields have on the stability of the guanine-cytosine proton transfer tautomers within a realistic strand of aqueous DNA using a combination of ensemble-based classical molecular dynamics (MD) coupled to quantum mechanics/molecular mechanics (QM/MM). Performing an ensemble of calculations accounts for the stochastic aspects of the simulations while allowing for easier identification of systematic errors. The methodology applied in this work has previously been shown to estimate base pair proton transfer rate coefficients that are in good agreement with recent experimental data. A range of electric fields in the order of 104 to 109 V m-1 is investigated based on their real-life medicinal applications which include gene therapy and cancer treatments. The MD trajectories confirm that electric fields up to 1.00 × 109 V m-1 have a negligible influence on the structure of the base pairs within DNA. The QM/MM results show that the application of large external electric fields (1.00 × 109 V m-1) parallel to the hydrogen bonds increases the thermodynamic population of the tautomers by up to one order of magnitude; moreover, the lifetimes of the tautomers remain insignificant when compared to the timescale of DNA replication.
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Affiliation(s)
- Alexander Gheorghiu
- Centre for Computational Science, University College London, 20 Gordon St, London, WC1H 0AJ, UK.
| | - Peter V Coveney
- Centre for Computational Science, University College London, 20 Gordon St, London, WC1H 0AJ, UK. and Informatics Institute, University of Amsterdam, P.O. Box 94323 1090 GH, Amsterdam, The Netherlands
| | - Alya A Arabi
- Centre for Computational Science, University College London, 20 Gordon St, London, WC1H 0AJ, UK. and College of Medicine and Health Sciences, Biochemistry Department, United Arab Emirates University, AlAin, P. O. Box: 17666, United Arab Emirates.
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35
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Yilmaz N, Kodama Y, Numata K. Lipid Membrane Interaction of Peptide/DNA Complexes Designed for Gene Delivery. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:1882-1893. [PMID: 33440939 DOI: 10.1021/acs.langmuir.0c03320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Among gene delivery systems, peptide-based gene carriers have received significant attention because of their selectivity, biocompatibility, and biodegradability. Since cellular membranes function as a barrier toward exogenous molecules, cell-penetrating peptides (CPPs), which are usually cationic and/or amphiphilic, can serve as efficient carriers to deliver cargo into the cytosol. Here, we examined the interactions of carrier peptides and their DNA complexes with lipid membranes using a quartz crystal microbalance (QCM) and high-speed atomic force microscopy (HS-AFM). The carrier peptides are a 12-residue partial presequence of yeast cytochrome c oxidase subunit IV (Cytcox) and BP100, which are a mitochondria-targeting signal peptide and a CPP, respectively. QCM data showed that BP100 has a higher binding affinity than Cytcox to both plasma membrane- and mitochondrial membrane-mimicking lipid bilayers. The DNA complexes with either Cytcox or BP100 exhibited the same tendency. Furthermore, HS-AFM data demonstrated that the DNA complexes of either peptide can disrupt the lipid membranes, forming larger pores in the case of Cytcox. Our results suggest that the binding affinity of the peptide/DNA complex to the plasma membrane is more critical than its membrane disruption ability in enhancing the cellular uptake of DNA.
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Affiliation(s)
- Neval Yilmaz
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan
| | - Yutaka Kodama
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan
- Center for Bioscience Research & Education, Utsunomiya University, Tochigi 321-8505, Japan
| | - Keiji Numata
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan
- Laboratory for Biomaterial Chemistry, Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 606-8501, Japan
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36
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Chen P, Vorobyov I, Roux B, Allen TW. Molecular Dynamics Simulations Based on Polarizable Models Show that Ion Permeation Interconverts between Different Mechanisms as a Function of Membrane Thickness. J Phys Chem B 2021; 125:1020-1035. [PMID: 33493394 DOI: 10.1021/acs.jpcb.0c08613] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Different mechanisms have been proposed to explain the permeation of charged compounds through lipid membranes. Overall, it is expected that an ion-induced defect permeation mechanism, where substantial membrane deformations accompany ion movement, should be dominant in thin membranes but that a solubility-diffusion mechanism, where ions partition into the membrane core with large associated dehydration energy costs, becomes dominant in thicker membranes. However, while this physical picture is intuitively reasonable, capturing the interconversion between these two permeation mechanisms in molecular dynamics (MD) simulations based on atomic models is challenging. In particular, simulations relying on nonpolarizable force fields are artificially unfavorable to the solubility-diffusion mechanism, as induced polarization of the nonpolar hydrocarbon is ignored, causing overestimated free energy costs for charged molecules to enter into this region of the membrane. In this study, all-atom MD simulations based on nonpolarizable and polarizable force fields are used to quantitatively characterize the permeation process for the arginine side chain analog methyl-guanidinium through bilayer membranes of mono-unsaturated phosphatidylcholine lipids with and without cholesterol, resulting in thicknesses spanning from ∼24 to ∼42 Å. With simulations based on a nonpolarizable force field, ion translocation can take place solely through an ion-induced defect mechanism, with free energy barriers increasing linearly from 14 to 40 kcal/mol, depending on the thickness. However, with simulations based on a polarizable force field, ion translocation is predominantly dominated by an ion-induced defect mechanism in thin membranes, which progressively converts to a solubility-diffusion mechanism as the membranes get thicker. The transition between the two mechanisms occurs at a thickness of ∼29 Å, with lipid tails of 22 or more carbon atoms. This situation appears to represent the upper limit for ion-induced defect permeation within the current polarizable models. Beyond this thickness, it becomes energetically preferable for the ion to dehydrate and partition into the membrane core-a phenomenon that cannot be captured using the nonpolarizable models. Induced electronic polarizability therefore leads not just to a shift in permeation energetics but to an interconversion between two strikingly different physical mechanisms. The result highlights the importance of induced polarizability in modeling lipid membranes.
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Affiliation(s)
- Peiran Chen
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Igor Vorobyov
- Department of Physiology & Membrane Biology, Department of Pharmacology, University of California, Davis, California 95616, United States
| | - Benoît Roux
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Toby W Allen
- School of Science, RMIT University, Melbourne 3001, Australia
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37
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Batta G, Kárpáti L, Henrique GF, Tarapcsák S, Kovács T, Zákány F, Mándity IM, Nagy P. Statin-boosted cellular uptake of penetratin due to reduced membrane dipole potential.. [DOI: 10.1101/2020.08.04.236984] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
AbstractSince cell penetrating peptides are promising tools for delivery of cargo into cells, factors limiting or facilitating their cellular uptake are intensely studied. Using labeling with pH-insensitive and pH-sensitive dyes we report that escape of penetratin from acidic endo-lysosomal compartments is retarded compared to its cellular uptake. The membrane dipole potential, known to alter transmembrane transport of charged molecules, is shown to be negatively correlated with the concentration of penetratin in the cytoplasmic compartment. Treatment of cells with therapeutically relevant concentrations of atorvastatin, an inhibitor of HMG-CoA reductase and cholesterol synthesis, significantly increased the release of penetratin from acidic endocytic compartments in two different cell types. This effect of atorvastatin correlated with its ability to decrease the membrane dipole potential. These results highlight the importance of the dipole potential in regulating cellular uptake of cell penetrating peptides and suggest a clinically relevant way of boosting this process.
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38
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Direct and indirect cholesterol effects on membrane proteins with special focus on potassium channels. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158706. [DOI: 10.1016/j.bbalip.2020.158706] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 03/19/2020] [Accepted: 03/30/2020] [Indexed: 12/16/2022]
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39
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Filipe HAL, Moreno MJ, Loura LMS. The Secret Lives of Fluorescent Membrane Probes as Revealed by Molecular Dynamics Simulations. Molecules 2020; 25:E3424. [PMID: 32731549 PMCID: PMC7435664 DOI: 10.3390/molecules25153424] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/23/2020] [Accepted: 07/25/2020] [Indexed: 12/15/2022] Open
Abstract
Fluorescent probes have been employed for more than half a century to study the structure and dynamics of model and biological membranes, using spectroscopic and/or microscopic experimental approaches. While their utilization has led to tremendous progress in our knowledge of membrane biophysics and physiology, in some respects the behavior of bilayer-inserted membrane probes has long remained inscrutable. The location, orientation and interaction of fluorophores with lipid and/or water molecules are often not well known, and they are crucial for understanding what the probe is actually reporting. Moreover, because the probe is an extraneous inclusion, it may perturb the properties of the host membrane system, altering the very properties it is supposed to measure. For these reasons, the need for independent methodologies to assess the behavior of bilayer-inserted fluorescence probes has been recognized for a long time. Because of recent improvements in computational tools, molecular dynamics (MD) simulations have become a popular means of obtaining this important information. The present review addresses MD studies of all major classes of fluorescent membrane probes, focusing in the period between 2011 and 2020, during which such work has undergone a dramatic surge in both the number of studies and the variety of probes and properties accessed.
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Affiliation(s)
- Hugo A. L. Filipe
- Chemistry Department, Coimbra Chemistry Center, Faculty of Sciences and Technology, University of Coimbra, 3004-535 Coimbra, Portugal;
| | - Maria João Moreno
- Coimbra Chemistry Center and CNC—Center for Neuroscience and Cell Biology, Chemistry Department, Faculty of Sciences and Technology, University of Coimbra, 3004-535 Coimbra, Portugal;
| | - Luís M. S. Loura
- Coimbra Chemistry Center and CNC—Center for Neuroscience and Cell Biology, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
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40
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Dalstein L, Huang JR, Wen YC. Wavelength-scanning second-harmonic generation for determining absolute charge density at aqueous interfaces. OPTICS LETTERS 2020; 45:3733-3736. [PMID: 32630941 DOI: 10.1364/ol.396002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 05/31/2020] [Indexed: 06/11/2023]
Abstract
We develop a new, to the best of our knowledge, optical scheme based on second-harmonic generation (SHG) at multiple wavelengths for unequivocal separation of the second-order and the electric-field-induced third-order nonlinear optical contributions from aqueous interfaces. The third-order SHG originating from the field-induced reorientation order of water molecules in the electrical double layer offers an optical label-free and inherent probe to the surface charge density and surface potential in the absolute scales. We verify this wavelength-scanning SHG scheme both theoretically and experimentally, and show that the approach is applicable to water interfaces with bulk ionic strength below 500 µM and can achieve a detection sensitivity for a surface charge density of ∼10-4C/m2.
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41
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Efimova SS, Zakharova AA, Ostroumova OS. Alkaloids Modulate the Functioning of Ion Channels Produced by Antimicrobial Agents via an Influence on the Lipid Host. Front Cell Dev Biol 2020; 8:537. [PMID: 32695785 PMCID: PMC7339123 DOI: 10.3389/fcell.2020.00537] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/08/2020] [Indexed: 12/22/2022] Open
Abstract
It is widely recognized that an alteration in membrane physical properties induced by the adsorption of various drugs and biologically active compounds might greatly affect the functioning of peptides and proteins embedded in the membrane, in particular various ion channels. This study aimed to obtain deep insight into the diversity of the molecular mechanisms of membrane action of one of the most numerous and extremely important class of phytochemicals, the alkaloids. Protoalkaloids (derivatives of β-phenylethylamine, benzylamines, and colchicines), heterocyclic alkaloids (derivatives of purine, quinolysidine, piperidine, pyridine, quinoline, and isoquinoline), and steroid alkaloids were tested. We evaluated the effects of 22 compounds on lipid packing by investigating the thermotropic behavior of membrane lipids and the leakage of a fluorescent marker from unilamellar lipid vesicles. The alteration in the transmembrane distribution of the electrical potential was estimated by measuring the alkaloid induced changes in the boundary potential of planar lipid bilayers. We found that benzylamines, the chili pepper active components, capsaicin and dihydrocapsaicin, strongly affect not only the elastic properties of the lipid host, but also its electrostatics by dramatic decrease in membrane dipole potential. We concluded that the increase in the conductance and lifetime of gramicidin A channels induced by benzylamines was related to alteration in membrane dipole potential not to decrease in membrane stiffness. A sharp decrease in the lifetime of single ion pores induced by the antifungal lipopeptide syringomycin E, after addition of benzylamines and black pepper alkaloid piperine, was also mainly due to the reduction in dipole potential. At the same time, we showed that the disordering of membrane lipids in the presence of benzylamines and piperine plays a decisive role in the regulation of the conductance induced by the antifungal polyene macrolide antibiotic nystatin, while the inhibition of steady-state transmembrane current produced by the antimicrobial peptide cecropin A was attributed to both the dipole potential drop and membrane lipid disordering in the presence of pepper alkaloids. These data might lead to a better understanding of the biological activity of alkaloids, especially their action on voltage-gated and mechanosensitive ion channels in cell membranes.
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Affiliation(s)
- Svetlana S Efimova
- Laboratory of Membrane and Ion Channel Modeling, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Anastasiia A Zakharova
- Laboratory of Membrane and Ion Channel Modeling, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Olga S Ostroumova
- Laboratory of Membrane and Ion Channel Modeling, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
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42
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Shankla M, Aksimentiev A. Molecular Transport across the Ionic Liquid-Aqueous Electrolyte Interface in a MoS 2 Nanopore. ACS APPLIED MATERIALS & INTERFACES 2020; 12:26624-26634. [PMID: 32393017 PMCID: PMC7292782 DOI: 10.1021/acsami.0c04523] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Nanopore sequencing of DNA has been enabled by the use of a biological enzyme to thread DNA through an engineered biological nanopore while recording the ionic current flowing through the nanopore. Efforts to realize a similar concept using a solid-state nanopore have been met with several technical challenges, one of which is the high speed of DNA translocation and the other the low ionic current contrast among individual nucleotides. A promising avenue to addressing both problems is using an ionic liquid to slow DNA translocation and a tiny nanopore in the MoS2 membrane to distinguish individual nucleotides. The physical mechanisms enabling these technical advances have remained elusive. Here, we characterize the ion and DNA transport through the ionic liquid/aqueous electrolyte interface, with and without a MoS2 nanopore, using the all-atom molecular dynamics method. We find that the partial miscibility of the ionic liquid and the aqueous electrolyte considerably alters the physics of the nanopore translocation process. Thus, the interface of the two phases generates a contact potential of 600 mV, the ionic current is dominated by the motion of ionic liquid molecules through the aqueous solution phase, and the DNA nucleotides exhibit preferential partitioning into the aqueous electrolyte, which leads to spontaneous transport of DNA polymers from the ionic liquid to the aqueous solution compartment in the absence of external voltage bias. The complex physics of the two-phase nanopore system offers a multitude of opportunities for extending the functionality of nanopore-sensing platforms.
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Affiliation(s)
- Manish Shankla
- Department of Physics, University of Illinois, 1110 West Green Street, Urbana, Illinois 61801, United States
| | - Aleksei Aksimentiev
- Department of Physics, University of Illinois, 1110 West Green Street, Urbana, Illinois 61801, United States
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43
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Shahoei R, Tajkhorshid E. Menthol Binding to the Human α4β2 Nicotinic Acetylcholine Receptor Facilitated by Its Strong Partitioning in the Membrane. J Phys Chem B 2020; 124:1866-1880. [PMID: 32048843 PMCID: PMC7094167 DOI: 10.1021/acs.jpcb.9b10092] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We utilize various computational methodologies to study menthol's interaction with multiple organic phases, a lipid bilayer, and the human α4β2 nicotinic acetylcholine receptor (nAChR), the most abundant nAChR in the brain. First, force field parameters developed for menthol are validated in alchemical free energy perturbation simulations to calculate solvation free energies of menthol in water, dodecane, and octanol and compare the results against experimental data. Next, umbrella sampling is used to construct the free energy profile of menthol permeation across a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayer. The results from a flooding simulation designed to study the water-membrane partitioning of menthol in a POPC lipid bilayer are used to determine the penetration depth and the preferred orientation of menthol in the bilayer. Finally, employing both docking and flooding simulations, menthol is shown to bind to different sites on the human α4β2 nAChR. The most likely binding mode of menthol to a desensitized membrane-embedded α4β2 nAChR is identified to be via a membrane-mediated pathway in which menthol binds to the sites at the lipid-protein interface after partitioning in the membrane. A rare but distinct binding mode in which menthol binds to the extracellular opening of receptor's ion permeation pore is also reported.
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Affiliation(s)
- Rezvan Shahoei
- Department of Physics, NIH Center for Macromolecular Modeling and Bioinformatics, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Emad Tajkhorshid
- Department of Biochemistry, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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44
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Effect of dipole moment on amphiphile solubility and partition into liquid ordered and liquid disordered phases in lipid bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183157. [PMID: 31846646 DOI: 10.1016/j.bbamem.2019.183157] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 12/01/2019] [Accepted: 12/12/2019] [Indexed: 12/20/2022]
Abstract
Association of amphiphiles with biomembranes is important for their availability at specific locations in organisms and cells, being critical for their biological function. A prominent role is usually attributed to the hydrophobic effect, and to electrostatic interactions between charged amphiphiles and lipids. This work explores a closely related and complementary aspect, namely the contribution made by dipole moments to the strength of the interactions established. Two xanthene amphiphiles with opposite relative orientations of their dipole and amphiphilic moments have been selected (Rhodamine-C14 and Carboxyfluorescein-C14). The membranes studied have distinct lipid compositions, representing typical cell membrane pools, ranging from internal membranes to the outer and inner leaflet of the plasma membrane. A comprehensive study is reported, including the affinity of the amphiphiles for the different membranes, the stability of the amphiphiles as monomers and their tendency to form small clusters, as well as their transverse location in the membrane. The orientation of the amphiphile dipole moment, which determines whether its interaction with the membrane dipole potential is repulsive or attractive, is found to exert a large influence on the association of the amphiphile with ordered lipid membranes. These interactions are also responsible for the formation of small clusters or stabilization of amphiphile monomers in the membrane. The results obtained allow understanding the prevalence of protein lipidation at the N-terminal for efficient targeting to the plasma membrane, as well as the tendency of GPI-anchored proteins (usually lipidated at the C-terminal) to form small clusters in the membrane ordered domains.
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45
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Li S, Wu L, Zhang X, Jiang X. The Structure of Water Bonded to Phosphate Groups at the Electrified Zwitterionic Phospholipid Membranes/Aqueous Interface. Angew Chem Int Ed Engl 2020; 59:6627-6630. [DOI: 10.1002/anie.202000511] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Indexed: 12/17/2022]
Affiliation(s)
- Shanshan Li
- State Key Laboratory of Electroanalytical ChemistryChangchun Institute of Applied ChemistryChinese Academy of Sciences Changchun 130022, Jilin China
- University of Science and Technology of China Hefei Anhui 230029 P. R. China
| | - Lie Wu
- State Key Laboratory of Electroanalytical ChemistryChangchun Institute of Applied ChemistryChinese Academy of Sciences Changchun 130022, Jilin China
| | - Xiaofei Zhang
- State Key Laboratory of Electroanalytical ChemistryChangchun Institute of Applied ChemistryChinese Academy of Sciences Changchun 130022, Jilin China
- University of Science and Technology of China Hefei Anhui 230029 P. R. China
| | - Xiue Jiang
- State Key Laboratory of Electroanalytical ChemistryChangchun Institute of Applied ChemistryChinese Academy of Sciences Changchun 130022, Jilin China
- University of Science and Technology of China Hefei Anhui 230029 P. R. China
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46
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Li S, Wu L, Zhang X, Jiang X. The Structure of Water Bonded to Phosphate Groups at the Electrified Zwitterionic Phospholipid Membranes/Aqueous Interface. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202000511] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Shanshan Li
- State Key Laboratory of Electroanalytical ChemistryChangchun Institute of Applied ChemistryChinese Academy of Sciences Changchun 130022, Jilin China
- University of Science and Technology of China Hefei Anhui 230029 P. R. China
| | - Lie Wu
- State Key Laboratory of Electroanalytical ChemistryChangchun Institute of Applied ChemistryChinese Academy of Sciences Changchun 130022, Jilin China
| | - Xiaofei Zhang
- State Key Laboratory of Electroanalytical ChemistryChangchun Institute of Applied ChemistryChinese Academy of Sciences Changchun 130022, Jilin China
- University of Science and Technology of China Hefei Anhui 230029 P. R. China
| | - Xiue Jiang
- State Key Laboratory of Electroanalytical ChemistryChangchun Institute of Applied ChemistryChinese Academy of Sciences Changchun 130022, Jilin China
- University of Science and Technology of China Hefei Anhui 230029 P. R. China
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47
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Ma T, Feng X, Ohori T, Miyata R, Tadaki D, Yamaura D, Deguchi T, Komiya M, Kanomata K, Hirose F, Niwano M, Hirano-Iwata A. Modulation of Photoinduced Transmembrane Currents in a Fullerene-Doped Freestanding Lipid Bilayer by a Lateral Bias. ACS OMEGA 2019; 4:18299-18303. [PMID: 31720530 PMCID: PMC6844088 DOI: 10.1021/acsomega.9b02336] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/10/2019] [Indexed: 06/01/2023]
Abstract
We report on a novel lipid bilayer system, in which a lateral bias can be applied in addition to a conventional transmembrane voltage. Freestanding bilayer lipid membranes (BLMs) doped with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) were formed in a microaperture, around which metal electrodes were deposited. Using this system, it was possible to modulate and amplify photoinduced transmembrane currents by applying a lateral bias along the BLM. The results indicate that the microfabricated Si chip with embedded electrodes is a promising platform for the formation of transistor-like devices based on PCBM-doped BLMs and have potential for use in a wide variety of nanohybrid devices.
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Affiliation(s)
- Teng Ma
- Advanced
Institute for Materials Research (WPI-AIMR) and Research Institute
of Electrical Communication, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
| | - Xingyao Feng
- Advanced
Institute for Materials Research (WPI-AIMR) and Research Institute
of Electrical Communication, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
| | - Takeshi Ohori
- Advanced
Institute for Materials Research (WPI-AIMR) and Research Institute
of Electrical Communication, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
| | - Ryusuke Miyata
- Advanced
Institute for Materials Research (WPI-AIMR) and Research Institute
of Electrical Communication, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
| | - Daisuke Tadaki
- Advanced
Institute for Materials Research (WPI-AIMR) and Research Institute
of Electrical Communication, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
| | - Daichi Yamaura
- Advanced
Institute for Materials Research (WPI-AIMR) and Research Institute
of Electrical Communication, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
| | - Takafumi Deguchi
- Advanced
Institute for Materials Research (WPI-AIMR) and Research Institute
of Electrical Communication, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
| | - Maki Komiya
- Advanced
Institute for Materials Research (WPI-AIMR) and Research Institute
of Electrical Communication, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
| | - Kensaku Kanomata
- Graduate
School of Science and Engineering, Yamagata
University, 4-3-16 Jonan, Yonezawa 992-8510, Japan
| | - Fumihiko Hirose
- Graduate
School of Science and Engineering, Yamagata
University, 4-3-16 Jonan, Yonezawa 992-8510, Japan
| | - Michio Niwano
- Kansei
Fukushi Research Institute, Tohoku Fukushi
University, 6-149-1 Kunimi-ga-oka, Aoba-ku, Sendai, Miyagi 989-3201, Japan
| | - Ayumi Hirano-Iwata
- Advanced
Institute for Materials Research (WPI-AIMR) and Research Institute
of Electrical Communication, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
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48
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Shahane G, Ding W, Palaiokostas M, Azevedo HS, Orsi M. Interaction of Antimicrobial Lipopeptides with Bacterial Lipid Bilayers. J Membr Biol 2019; 252:317-329. [PMID: 31098677 PMCID: PMC6790193 DOI: 10.1007/s00232-019-00068-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 05/03/2019] [Indexed: 02/07/2023]
Abstract
The resistance of pathogens to traditional antibiotics is currently a global issue of enormous concern. As the discovery and development of new antibiotics become increasingly challenging, synthetic antimicrobial lipopeptides (AMLPs) are now receiving renewed attention as a new class of antimicrobial agents. In contrast to traditional antibiotics, AMLPs act by physically disrupting the cell membrane (rather than targeting specific proteins), thus reducing the risk of inducing bacterial resistance. In this study, we use microsecond-timescale atomistic molecular dynamics simulations to quantify the interaction of a short AMLP (C16-KKK) with model bacterial lipid bilayers. In particular, we investigate how fundamental transmembrane properties change in relation to a range of lipopeptide concentrations. A number of structural, mechanical, and dynamical features are found to be significantly altered in a non-linear fashion. At 10 mol% concentration, lipopeptides have a condensing effect on bacterial bilayers, characterized by a decrease in the area per lipid and an increase in the bilayer order. Higher AMLP concentrations of 25 and 40 mol% destabilize the membrane by disrupting the bilayer core structure, inducing membrane thinning and water leakage. Important transmembrane properties such as the lateral pressure and dipole potential profiles are also affected. Potential implications on membrane function and associated proteins are discussed.
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Affiliation(s)
- Ganesh Shahane
- Institute of Bioengineering, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Wei Ding
- School of Engineering & Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Michail Palaiokostas
- School of Engineering & Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Helena S Azevedo
- School of Engineering & Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Mario Orsi
- Department of Applied Sciences, University of the West of England, Coldharbour Lane, Bristol, BS16 1QY, UK.
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49
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Ermakov YA, Asadchikov VE, Roschin BS, Volkov YO, Khomich DA, Nesterenko AM, Tikhonov AM. Comprehensive Study of the Liquid Expanded-Liquid Condensed Phase Transition in 1,2-Dimyristoyl- sn-glycero-3-phospho-l-serine Monolayers: Surface Pressure, Volta Potential, X-ray Reflectivity, and Molecular Dynamics Modeling. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:12326-12338. [PMID: 31480848 DOI: 10.1021/acs.langmuir.9b01450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
An integrated approach is applied to reveal fine changes in the surface-normal structure of 1,2-dimyristoyl-sn-glycero-3-phospho-l-serine (DMPS) monolayers at the air-lipid-water interface occurring in a liquid expanded (LE)-liquid condensed (LC) transition. The combination of the Langmuir monolayer technique, X-ray reflectometry, and molecular dynamics (MD) modeling provides new insight into the molecular nature of electrostatic phenomena in different stages of lipid compression. A homemade setup with a laboratory X-ray source (λ = 1.54 Å) offers a nondestructive way to reveal the structural difference between the LE and LC phases of the lipid. The electron density profile in the direction normal to the interface is recovered from the X-ray reflectivity data with the use of both model-independent and model-based approaches. MD simulations of the DMPS monolayer are performed for several areas per lipid using the all-atom force field. Using the conventional theory of capillary waves, a comparison is made between the electron density profiles reconstructed from the X-ray data and those calculated directly from MD modeling, which demonstrates remarkable agreement between the experiment and simulations for all selected lipid densities. This confirms the validity of the simulations and allows an analysis of the contributions of the hydrophobic tails and hydrated polar groups to the electron density profile and to the dipole component of the electric field at the interface. According to the MD data, the dependence of the Volta potential on the area per lipid in the monolayer has a different molecular nature below and above the phase transition. In the LE state of the monolayer, the potential is determined mostly by the oriented water molecules in the polar region of the lipid. In the LE-LC transition, these molecules are displaced to the bulk, and their effect on the Volta potential becomes insignificant compared with the contribution of the hydrophobic tails. The hydrophobic tails are highly ordered in the state of the liquid crystal so that their dipole moments entirely determine the growth of the potential upon compression up to the monolayer collapse.
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Affiliation(s)
- Yu A Ermakov
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences , Leninsky pr., 31/4 , Moscow 119071 , Russia
| | - V E Asadchikov
- Shubnikov Institute of Crystallography , Federal Research Center Crystallography and Photonics, Russian Academy of Sciences , Leninsky pr., 59 , Moscow 119333 , Russia
| | - B S Roschin
- Shubnikov Institute of Crystallography , Federal Research Center Crystallography and Photonics, Russian Academy of Sciences , Leninsky pr., 59 , Moscow 119333 , Russia
| | - Yu O Volkov
- Shubnikov Institute of Crystallography , Federal Research Center Crystallography and Photonics, Russian Academy of Sciences , Leninsky pr., 59 , Moscow 119333 , Russia
- Institute of Solid State Physics, Russian Academy of Sciences , Academician Ossipyan str. 2 , Moscow District, Chernogolovka 142432 , Russia
| | - D A Khomich
- Lomonosov Moscow State University , Biology Faculty, Leninskie gory 1/12 , Moscow 119234 , Russia
- Engelhardt Institute of Molecular Biology , Russian Academy of Sciences , Vavilova, 32 , Moscow 119991 , Russia
| | - A M Nesterenko
- Belozersky Institute of Physico-Chemical Biology , Lomonosov Moscow State University ; Leninskie gory 1/40 , Moscow , 119991 , Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry , Russian Academy of Sciences , Miklukho-Maklaya 16/10 , Moscow 117997 , Russia
| | - A M Tikhonov
- Institute of Solid State Physics, Russian Academy of Sciences , Academician Ossipyan str. 2 , Moscow District, Chernogolovka 142432 , Russia
- Kapitza Institute for Physical Problems, Russian Academy of Sciences , ul. Kosygina 2 , Moscow 119334 , Russia
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50
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Lazzari-Dean JR, Gest AM, Miller EW. Optical estimation of absolute membrane potential using fluorescence lifetime imaging. eLife 2019; 8:44522. [PMID: 31545164 PMCID: PMC6814365 DOI: 10.7554/elife.44522] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 09/16/2019] [Indexed: 12/29/2022] Open
Abstract
All cells maintain ionic gradients across their plasma membranes, producing transmembrane potentials (Vmem). Mounting evidence suggests a relationship between resting Vmem and the physiology of non-excitable cells with implications in diverse areas, including cancer, cellular differentiation, and body patterning. A lack of non-invasive methods to record absolute Vmem limits our understanding of this fundamental signal. To address this need, we developed a fluorescence lifetime-based approach (VF-FLIM) to visualize and optically quantify Vmem with single-cell resolution in mammalian cell culture. Using VF-FLIM, we report Vmem distributions over thousands of cells, a 100-fold improvement relative to electrophysiological approaches. In human carcinoma cells, we visualize the voltage response to growth factor stimulation, stably recording a 10-15 mV hyperpolarization over minutes. Using pharmacological inhibitors, we identify the source of the hyperpolarization as the Ca2+-activated K+ channel KCa3.1. The ability to optically quantify absolute Vmem with cellular resolution will allow a re-examination of its signaling roles.
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Affiliation(s)
- Julia R Lazzari-Dean
- Department of Chemistry, University of California, Berkeley, Berkeley, United States
| | - Anneliese Mm Gest
- Department of Chemistry, University of California, Berkeley, Berkeley, United States
| | - Evan W Miller
- Department of Chemistry, University of California, Berkeley, Berkeley, United States.,Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, United States.,Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States
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