1
|
Socrier L, Sharma A, Chen T, Flato K, Kettelhoit K, Enderlein J, Werz DB, Steinem C. Fluorophore position of headgroup-labeled Gb 3 glycosphingolipids in lipid bilayers. Biophys J 2023; 122:4104-4112. [PMID: 37735870 PMCID: PMC10598288 DOI: 10.1016/j.bpj.2023.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 08/28/2023] [Accepted: 09/18/2023] [Indexed: 09/23/2023] Open
Abstract
Fluorescent lipid probes are an invaluable tool for investigating lipid membranes. In particular, localizing certain receptor lipids such as glycosphingolipids within phase-separated membranes is of pivotal interest to understanding the influence of protein-receptor lipid binding on membrane organization. However, fluorescent labeling can readily alter the phase behavior of a lipid membrane because of the interaction of the fluorescent moiety with the membrane interface. Here, we investigated Gb3 glycosphingolipids, serving as receptor lipids for the protein Shiga toxin, with a headgroup attached BODIPY fluorophore separated by a polyethylene glycol (PEG) spacer of different lengths. We found that the diffusion coefficients of the fluorescently labeled Gb3 species in 1,2-dioleoyl-sn-glycero-3-phosphocholine/Gb3 (98:2, n/n) supported lipid bilayers are unaltered by the PEG spacer length. However, quenching as well as graphene-induced energy transfer experiments indicated that the length of the PEG spacer (n = 3 and n = 13) alters the position of the BODIPY fluorophore. In particular, the graphene-induced energy transfer technique provided accurate end-to-end distances between the fluorophores in the two leaflets of the bilayer thus enabling us to quantify the distance between the membrane interface and the fluorophore with sub-nanometer resolution. The spacer with three oligo ethylene glycol groups positioned the BODIPY fluorophore directly at the membrane interface favoring its interaction with the bilayer and thus may disturb lipid packing. However, the longer PEG spacer (n = 13) separated the BODIPY moiety from the membrane surface by 1.5 nm.
Collapse
Affiliation(s)
- Larissa Socrier
- Max-Planck-Institute for Dynamics and Self-Organization, Göttingen, Germany
| | - Akshita Sharma
- III. Institute of Physics - Biophysics, Georg-August-Universität, Göttingen, Germany
| | - Tao Chen
- III. Institute of Physics - Biophysics, Georg-August-Universität, Göttingen, Germany
| | - Kira Flato
- Institute of Organic and Biomolecular Chemistry, Georg-August-Universität, Göttingen, Germany
| | | | - Jörg Enderlein
- III. Institute of Physics - Biophysics, Georg-August-Universität, Göttingen, Germany
| | - Daniel B Werz
- Institute of Organic Chemistry, Albert-Ludwigs-Universität, Freiburg, Germany
| | - Claudia Steinem
- Max-Planck-Institute for Dynamics and Self-Organization, Göttingen, Germany; Institute of Organic and Biomolecular Chemistry, Georg-August-Universität, Göttingen, Germany.
| |
Collapse
|
2
|
Gracheva IA, Tretiakova DS, Zamyshlyaeva OG, Kudriashova ES, Vodovozova EL, Fedorov AY, Boldyrev IA. Cy5-Labeled Phosphatidylcholine. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2021. [DOI: 10.1134/s1068162021050265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
3
|
Alekseeva AS, Volynsky PE, Boldyrev IA. Estimation of the Phospholipase A2 Selectivity on POPC/POPG Membranes Using the Interaction Map. BIOCHEMISTRY (MOSCOW), SUPPLEMENT SERIES A: MEMBRANE AND CELL BIOLOGY 2021. [DOI: 10.1134/s1990747821050032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Abstract
The regulation of the activity and selectivity of phospholipase A2 (PLA2), which is capable of cleaving fatty acid in the second position (sn-2) of the phospholipid, is carried out through the membrane-binding and catalytic sites of the enzyme. For hydrolytic activity, PLA2 must first bind to the phospholipid membrane, and the binding efficiency depends on the composition of the membrane. The membrane-binding site of PLA2 is formed by several tens of amino acids and its composition differs from enzyme to enzyme; hydrophobic and positively charged amino acids play a key role in the interaction. In this work, we investigated the interaction of PLA2 from bee venom with phospholipid bilayers of palmitoyl oleoylphosphatidylcholine (POPC) containing different amounts of palmitoyloleoylphosphatidylglycerol (POPG). On the basis of the measurements of the protein intrinsic fluorescence and the anisotropy of the fluorescence of the lipid probe we propose the construction of lipid–protein interaction maps, which reflect both the efficiency of protein binding and changes in the structure of the membrane. These changes cause alterations in the fluorescence anisotropy of the label, which in turn is a measure of the mobility of the lipid environment of the fluorescent probe. Analysis of interaction maps showed that there is a relationship between lipid mobility and enzyme binding efficiency: the optimum interaction of PLA2 with membranes from a POPC/POPG mixture lies in the region of the highest lipid mobility, and not in the region of the highest negative charge. This dependence complements the existing understanding of the process of recognition of the membrane surface by the enzyme and the selection of lipids by the enzyme already bound to the membrane. The proposed mapping method can be extended to other membrane-active proteins.
Collapse
|
4
|
Owen MC, Karner A, Šachl R, Preiner J, Amaro M, Vácha R. Force Field Comparison of GM1 in a DOPC Bilayer Validated with AFM and FRET Experiments. J Phys Chem B 2019; 123:7504-7517. [PMID: 31397569 DOI: 10.1021/acs.jpcb.9b05095] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The great physiological relevance of glycolipids is being increasingly recognized, and glycolipid interactions have been shown to be central to cell-cell recognition, neuronal plasticity, protein-ligand recognition, and other important processes. However, detailed molecular-level understanding of these processes remains to be fully resolved. Molecular dynamics simulations could reveal the details of the glycolipid interactions, but the results may be influenced by the choice of the employed force field. Here, we have compared the behavior and properties of GM1, a common, biologically important glycolipid, using the CHARMM36, OPLS, GROMOS, and Amber99-GLYCAM06 (in bilayers comprising SLIPIDS and LIPID14 lipids) force fields in bilayers comprising 1,2-dioleoyl-sn-glycero-3-phosphocholine lipids and compared the results to atomic force microscopy and fluorescence resonance energy transfer experiments. We found discrepancies within the GM1 behavior displayed between the investigated force fields. Based on a direct comparison with complementary experimental results derived from fluorescence and AFM measurements, we recommend using the Amber99-GLYCAM force field in bilayers comprising LIPID14 or SLIPIDS lipids followed by CHARMM36 and OPLS force fields in simulations. The GROMOS force field is not recommended for reproducing the properties of the GM1 head group.
Collapse
Affiliation(s)
- Michael C Owen
- CEITEC - Central European Institute of Technology, Kamenice 5, 625 00 Brno, Czech Republic.,Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Andreas Karner
- University of Applied Sciences Upper Austria, 4020 Linz, Austria
| | - Radek Šachl
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the C.A.S., v.v.i., Dolejškova 2155/3, 182 23 Prague 8, Czech Republic
| | - Johannes Preiner
- University of Applied Sciences Upper Austria, 4020 Linz, Austria
| | - Mariana Amaro
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the C.A.S., v.v.i., Dolejškova 2155/3, 182 23 Prague 8, Czech Republic
| | - Robert Vácha
- CEITEC - Central European Institute of Technology, Kamenice 5, 625 00 Brno, Czech Republic.,Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| |
Collapse
|
5
|
Ma D, Xu C, Hou W, Zhao C, Ma J, Huang X, Jia Q, Ma L, Diao J, Liu C, Li M, Lu Y. Detecting Single‐Molecule Dynamics on Lipid Membranes with Quenchers‐in‐a‐Liposome FRET. Angew Chem Int Ed Engl 2019; 58:5577-5581. [DOI: 10.1002/anie.201813888] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 02/11/2019] [Indexed: 12/25/2022]
Affiliation(s)
- Dong‐Fei Ma
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Chun‐Hua Xu
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Wen‐Qing Hou
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Chun‐Yu Zhao
- Interdisciplinary Research Center on Biology and ChemistryShanghai Institute of Organic ChemistryChinese Academy of Sciences Shanghai 200032 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Jian‐Bing Ma
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Xing‐Yuan Huang
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Qi Jia
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Lu Ma
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Jiajie Diao
- Department of Cancer BiologyUniversity of Cincinnati School of Medicine Cincinnati OH 45267 USA
| | - Cong Liu
- Interdisciplinary Research Center on Biology and ChemistryShanghai Institute of Organic ChemistryChinese Academy of Sciences Shanghai 200032 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Ming Li
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
- Songshan Lake Materials Laboratory Dongguan Guangdong 523808 China
| | - Ying Lu
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
- Songshan Lake Materials Laboratory Dongguan Guangdong 523808 China
| |
Collapse
|
6
|
Ma D, Xu C, Hou W, Zhao C, Ma J, Huang X, Jia Q, Ma L, Diao J, Liu C, Li M, Lu Y. Detecting Single‐Molecule Dynamics on Lipid Membranes with Quenchers‐in‐a‐Liposome FRET. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201813888] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Dong‐Fei Ma
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Chun‐Hua Xu
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Wen‐Qing Hou
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Chun‐Yu Zhao
- Interdisciplinary Research Center on Biology and ChemistryShanghai Institute of Organic ChemistryChinese Academy of Sciences Shanghai 200032 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Jian‐Bing Ma
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Xing‐Yuan Huang
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Qi Jia
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Lu Ma
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Jiajie Diao
- Department of Cancer BiologyUniversity of Cincinnati School of Medicine Cincinnati OH 45267 USA
| | - Cong Liu
- Interdisciplinary Research Center on Biology and ChemistryShanghai Institute of Organic ChemistryChinese Academy of Sciences Shanghai 200032 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Ming Li
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
- Songshan Lake Materials Laboratory Dongguan Guangdong 523808 China
| | - Ying Lu
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy of Sciences Beijing 100049 China
- Songshan Lake Materials Laboratory Dongguan Guangdong 523808 China
| |
Collapse
|
7
|
Tretiakova D, Alekseeva A, Galimzyanov T, Boldyrev A, Chernyadyev A, Ermakov Y, Batishchev O, Vodovozova E, Boldyrev I. Lateral stress profile and fluorescent lipid probes. FRET pair of probes that introduces minimal distortions into lipid packing. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2337-2347. [DOI: 10.1016/j.bbamem.2018.05.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 05/17/2018] [Accepted: 05/30/2018] [Indexed: 12/31/2022]
|
8
|
Koukalová A, Pokorná Š, Boyle AL, Lopez Mora N, Kros A, Hof M, Šachl R. Distinct roles of SNARE-mimicking lipopeptides during initial steps of membrane fusion. NANOSCALE 2018; 10:19064-19073. [PMID: 30288507 DOI: 10.1039/c8nr05730c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A model system for membrane fusion, inspired by SNARE proteins and based on two complementary lipopeptides CPnE4 and CPnK4, has been recently developed. It consists of cholesterol (C), a poly(ethylene glycol) linker (Pn) and either a cationic peptide K4 (KIAALKE)4 or an anionic peptide E4 (EIAALEK)4. In this paper, fluorescence spectroscopy is used to decipher distinct but complementary roles of these lipopeptides during early stages of membrane fusion. Molecular evidence is provided that different distances of E4 in CPnE4 and K4 in CPnK4 from the bilayer represent an important mechanism, which enables fusion. Whereas E4 is exposed to the bulk and solely promotes membrane binding of CPnK4, K4 loops back to the lipid-water interface where it fulfills two distinct roles: it initiates bilayer contact by binding to CPnE4 containing bilayers; and it initiates fusion by modulating the bilayer properties. The interaction between CPnE4 and CPnK4 is severely down-regulated by binding of K4 to the bilayer and possible only if the lipopeptides approach each other as constituents of different bilayers. When the complementary lipopeptides are localized in the same bilayer, hetero-coiling is disabled. These data provide crucial insights as to how fusion is initiated and highlight the importance of both peptides in this process.
Collapse
Affiliation(s)
- Alena Koukalová
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, Prague, 182 23, Czech Republic.
| | | | | | | | | | | | | |
Collapse
|
9
|
Doskocz J, Drabik D, Chodaczek G, Przybyło M, Langner M. Statistical Analysis of Bending Rigidity Coefficient Determined Using Fluorescence-Based Flicker-Noise Spectroscopy. J Membr Biol 2018; 251:601-608. [PMID: 29858612 DOI: 10.1007/s00232-018-0037-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 05/29/2018] [Indexed: 10/14/2022]
Abstract
Bending rigidity coefficient describes propensity of a lipid bilayer to deform. In order to measure the parameter experimentally using flickering noise spectroscopy, the microscopic imaging is required, which necessitates the application of giant unilamellar vesicles (GUV) lipid bilayer model. The major difficulty associated with the application of the model is the statistical character of GUV population with respect to their size and the homogeneity of lipid bilayer composition, if a mixture of lipids is used. In the paper, the bending rigidity coefficient was measured using the fluorescence-enhanced flicker-noise spectroscopy. In the paper, the bending rigidity coefficient was determined for large populations of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and 1,2-dioleoyl-sn-glycero-3-phosphocholine vesicles. The quantity of obtained experimental data allows to perform statistical analysis aiming at the identification of the distribution, which is the most appropriate for the calculation of the value of the membrane bending rigidity coefficient. It has been demonstrated that the bending rigidity coefficient is characterized by an asymmetrical distribution, which is well approximated with the gamma distribution. Since there are no biophysical reasons for that we propose to use the difference between normal and gamma fits as a measure of the homogeneity of vesicle population. In addition, the effect of a fluorescent label and types of instrumental setups on determined values has been tested. Obtained results show that the value of the bending rigidity coefficient does not depend on the type of a fluorescent label nor on the type of microscope used.
Collapse
Affiliation(s)
- Joanna Doskocz
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Pl. Grunwaldzki 13, 50-377, Wrocław, Poland.
| | - Dominik Drabik
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Pl. Grunwaldzki 13, 50-377, Wrocław, Poland
| | - Grzegorz Chodaczek
- Wroclaw Research Centre EIT+, ul. Stabłowicka 147, 54-066, Wrocław, Poland
| | - Magdalena Przybyło
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Pl. Grunwaldzki 13, 50-377, Wrocław, Poland.,Lipid Systems sp. z o.o., ul. Krzemieniecka 48C, 54-613, Wrocław, Poland
| | - Marek Langner
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Pl. Grunwaldzki 13, 50-377, Wrocław, Poland.,Lipid Systems sp. z o.o., ul. Krzemieniecka 48C, 54-613, Wrocław, Poland
| |
Collapse
|
10
|
Alekseeva AS, Tretiakova DS, Melnikova DN, Molotkovsky UG, Boldyrev IA. Novel fluorescent membrane probe 2,3;5,6-bis(cyclohexyl)-BODIPY-labeled phosphatidylcholine. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2016. [DOI: 10.1134/s1068162016030031] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
11
|
Amaro M, Šachl R, Jurkiewicz P, Coutinho A, Prieto M, Hof M. Time-resolved fluorescence in lipid bilayers: selected applications and advantages over steady state. Biophys J 2016; 107:2751-2760. [PMID: 25517142 DOI: 10.1016/j.bpj.2014.10.058] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 10/23/2014] [Accepted: 10/29/2014] [Indexed: 01/23/2023] Open
Abstract
Fluorescence methods are versatile tools for obtaining dynamic and topological information about biomembranes because the molecular interactions taking place in lipid membranes frequently occur on the same timescale as fluorescence emission. The fluorescence intensity decay, in particular, is a powerful reporter of the molecular environment of a fluorophore. The fluorescence lifetime can be sensitive to the local polarity, hydration, viscosity, and/or presence of fluorescence quenchers/energy acceptors within several nanometers of the vicinity of a fluorophore. Illustrative examples of how time-resolved fluorescence measurements can provide more valuable and detailed information about a system than the time-integrated (steady-state) approach will be presented in this review: 1), determination of membrane polarity and mobility using time-dependent spectral shifts; 2), identification of submicroscopic domains by fluorescence lifetime imaging microscopy; 3), elucidation of membrane leakage mechanisms from dye self-quenching assays; and 4), evaluation of nanodomain sizes by time-resolved Förster resonance energy transfer measurements.
Collapse
Affiliation(s)
- Mariana Amaro
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic
| | - Radek Šachl
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic
| | - Piotr Jurkiewicz
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic
| | - Ana Coutinho
- Centre for Molecular Chemistry and Physics and Instituto de Nanociência e Nanotecnologia, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal; Departamento Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Manuel Prieto
- Centre for Molecular Chemistry and Physics and Instituto de Nanociência e Nanotecnologia, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Martin Hof
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic.
| |
Collapse
|
12
|
Xie Y, Chen J, Zhang S, Fan K, Chen G, Zhuang Z, Zeng M, Chen D, Lu L, Yang L, Yang F. The research about microscopic structure of emulsion membrane in O/W emulsion by NMR and its influence to emulsion stability. Int J Pharm 2016; 500:110-9. [PMID: 26784978 DOI: 10.1016/j.ijpharm.2016.01.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 01/02/2016] [Accepted: 01/14/2016] [Indexed: 12/08/2022]
Abstract
PURPOSE This paper discussed the influence of microstructure of emulsion membrane on O/W emulsion stability. METHODS O/W emulsions were emulsified with equal dosage of egg yolk lecithin and increasing dosage of co-emulsifier (oleic acid or HS15). The average particle size and centrifugal stability constant of emulsion, as well as interfacial tension between oil and water phase were determined. The microstructure of emulsion membrane had been studied by (1)H/(13)C NMR, meanwhile the emulsion droplets were visually presented with TEM and IFM. RESULTS With increasing dosage of co-emulsifier, emulsions showed two stable states, under which the signal intensity of characteristic group (orient to lipophilic core) of egg yolk lecithin disappeared in NMR of emulsions, but that (orient to aqueous phase) of co-emulsifiers only had some reduction at the second stable state. At the two stable states, the emulsion membranes were neater in TEM and emulsion droplets were rounder in IFM. Furthermore, the average particle size of emulsions at the second stable state was bigger than that at the first stable state. CONCLUSIONS Egg yolk lecithin and co-emulsifier respectively arranged into monolayer and bilayer emulsion membrane at the two stable states. The microstructure of emulsion membrane was related to the stability of emulsion.
Collapse
Affiliation(s)
- Yiqiao Xie
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Jisheng Chen
- Department of Pharmacy, First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Shu Zhang
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Kaiyan Fan
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Gang Chen
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Zerong Zhuang
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Mingying Zeng
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - De Chen
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Longgui Lu
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| | - Linlin Yang
- Guangdong Province Maternity and Child Care Hospital, Guangzhou, Guangdong 510006, China.
| | - Fan Yang
- Department of Pharmaceutics, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510006, China.
| |
Collapse
|
13
|
Drabik D, Przybyło M, Sikorski A, Langner M. The Effect of a Fluorophore Photo-Physics on the Lipid Vesicle Diffusion Coefficient Studied by Fluorescence Correlation Spectroscopy. J Fluoresc 2016; 26:661-9. [PMID: 26695945 PMCID: PMC4773467 DOI: 10.1007/s10895-015-1752-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 12/14/2015] [Indexed: 11/28/2022]
Abstract
Fluorescence Correlation Spectroscopy (FCS) is a technique, which allows determination of the diffusion coefficient and concentration of fluorescent objects suspended in the solution. The measured parameter is the fluctuation of the fluorescence signal emitted by diffusing molecules. When 100 nm DOPC vesicles labeled with various fluorescent dyes (Fluorescein-PE, NBD-PE, Atto488 DOPE or βBodipy FL) were measured, different values of diffusion coefficients have been obtained. These diffusion coefficients were different from the expected values measured using the dynamic light scattering method (DLS). The FCS was initially developed for solutions containing small fluorescent molecules therefore the observed inconsistency may result from the nature of vesicle suspension itself. The duration of the fluorescence signal may depend on the following factors: the exposure time of the labeled object to the excitation beam, the photo-physical properties (e.g., stability) of a fluorophore, the theoretical model used for the calculations of the diffusion coefficient and optical properties of the vesicle suspension. The diffusion coefficients determined for differently labeled liposomes show that its dependence on vesicle size and quantity of fluorescent probed used for labeling was significant demonstrating that the fluorescence properties of the fluorophore itself (bleaching and/or blinking) were critical factors for a correct outcome of FCS experiment. The new, based on combined FCS and DLS measurements, method for the determination of the focal volume prove itself to be useful for the evaluation of a fluorescence dye with respect to its applicability for FCS experiment.
Collapse
Affiliation(s)
- Dominik Drabik
- Laboratory for Biophysics of Macromolecular Aggregates, Department of Biomedical Engineering, Wroclaw University of Technology, Pl. Grunwaldzki 13, 50-377, Wroclaw, Poland.
| | - Magda Przybyło
- Laboratory for Biophysics of Macromolecular Aggregates, Department of Biomedical Engineering, Wroclaw University of Technology, Pl. Grunwaldzki 13, 50-377, Wroclaw, Poland
- Lipid Systems sp. z. o. o. [Ltd], ul. Duńska 9, 54-066, Wrocław, Poland
| | - Aleksander Sikorski
- Laboratory of Cytobiochemistry, Faculty of Biotechnology, University of Wroclaw, ul. Joliot-Curie 14a, Wrocław, Poland
| | - Marek Langner
- Laboratory for Biophysics of Macromolecular Aggregates, Department of Biomedical Engineering, Wroclaw University of Technology, Pl. Grunwaldzki 13, 50-377, Wroclaw, Poland
- Lipid Systems sp. z. o. o. [Ltd], ul. Duńska 9, 54-066, Wrocław, Poland
| |
Collapse
|
14
|
Denz M, Haralampiev I, Schiller S, Szente L, Herrmann A, Huster D, Müller P. Interaction of fluorescent phospholipids with cyclodextrins. Chem Phys Lipids 2015; 194:37-48. [PMID: 26232666 DOI: 10.1016/j.chemphyslip.2015.07.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 07/16/2015] [Accepted: 07/26/2015] [Indexed: 11/29/2022]
Abstract
Fluorescent analogs of phospholipids are often employed to investigate the structure and dynamics of lipids in membranes. Some of those studies have used cyclodextrins e.g., to modulate the lipid phase. However, the role of the fluorescence moiety of analogs for the interaction between cyclodextrins and fluorescent lipids has not been investigated so far in detail. Therefore, in the present study the interaction of various fluorescent phospholipid analogs with methylated α-, β- and γ- cyclodextrins was investigated. The analogs differed in their structure, in the length of the fatty acyl chain, in the position of the fluorescence group, and in the attached fluorescence moiety (7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) or dipyrrometheneboron difluoride (BODIPY)). In aqueous buffer, cyclodextrins bind fluorescent lipids disturbing the organization of the analogs. When incorporated into lipid vesicles, analogs are selectively extracted from the membrane upon addition of cyclodextrins. The results show that the interaction of cyclodextrins with fluorescent phospholipids depends on the cyclodextrin species, the fluorescence moiety and the phospholipid structure. The presented data should be of interest for studies using fluorescent phospholipids and cyclodextrins, since the interaction between the fluorescence group and the cyclodextrin may interfere with the process(es) under study.
Collapse
Affiliation(s)
- Manuela Denz
- Humboldt-Universität zu Berlin, Department of Biology, Invalidenstr. 42, D-10115 Berlin, Germany
| | - Ivan Haralampiev
- Humboldt-Universität zu Berlin, Department of Biology, Invalidenstr. 42, D-10115 Berlin, Germany
| | - Sabine Schiller
- Humboldt-Universität zu Berlin, Department of Biology, Invalidenstr. 42, D-10115 Berlin, Germany
| | - Lajos Szente
- Cyclolab Ltd., P.O. Box 435, H-1525, Budapest, Hungary
| | - Andreas Herrmann
- Humboldt-Universität zu Berlin, Department of Biology, Invalidenstr. 42, D-10115 Berlin, Germany
| | - Daniel Huster
- University of Leipzig, Institute of Medical Physics and Biophysics, Härtelstr. 16-18, D-04107 Leipzig, Germany
| | - Peter Müller
- Humboldt-Universität zu Berlin, Department of Biology, Invalidenstr. 42, D-10115 Berlin, Germany.
| |
Collapse
|
15
|
Demchenko AP, Duportail G, Oncul S, Klymchenko AS, Mély Y. Introduction to fluorescence probing of biological membranes. Methods Mol Biol 2015; 1232:19-43. [PMID: 25331125 DOI: 10.1007/978-1-4939-1752-5_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Fluorescence is one of the most powerful and commonly used tools in biophysical studies of biomembrane structure and dynamics that can be applied on different levels, from lipid monolayers and bilayers to living cells, tissues, and whole animals. Successful application of this method relies on proper design of fluorescence probes with optimized photophysical properties. These probes are efficient for studying the microscopic analogs of viscosity, polarity, and hydration, as well as the molecular order, environment relaxation, and electrostatic potentials at the sites of their location. Being smaller than the membrane width they can sense the gradients of these parameters across the membrane. We present examples of novel dyes that achieve increased spatial resolution and information content of the probe responses. In this respect, multiparametric environment-sensitive probes feature considerable promise.
Collapse
Affiliation(s)
- Alexander P Demchenko
- Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, 9 Leontovicha Street, Kiev, 01030, Ukraine,
| | | | | | | | | |
Collapse
|
16
|
Secretory phospholipase A2 activity in blood serum: The challenge to sense. Biochem Biophys Res Commun 2014; 454:178-82. [DOI: 10.1016/j.bbrc.2014.10.069] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 10/14/2014] [Indexed: 11/23/2022]
|
17
|
Olšinová M, Jurkiewicz P, Pozník M, Šachl R, Prausová T, Hof M, Kozmík V, Teplý F, Svoboda J, Cebecauer M. Di- and tri-oxalkyl derivatives of a boron dipyrromethene (BODIPY) rotor dye in lipid bilayers. Phys Chem Chem Phys 2014; 16:10688-97. [DOI: 10.1039/c4cp00888j] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Di- and tri-alkylated variants of a BODIPY rotor: carefully characterised probes sensing the liquid or gel state of lipid membranes.
Collapse
Affiliation(s)
- Marie Olšinová
- Department of Biophysical Chemistry
- J. Heyrovsky Institute of Physical Chemistry
- Academy of Sciences of the Czech Republic
- 18223 Prague, Czech Republic
| | - Piotr Jurkiewicz
- Department of Biophysical Chemistry
- J. Heyrovsky Institute of Physical Chemistry
- Academy of Sciences of the Czech Republic
- 18223 Prague, Czech Republic
| | - Michal Pozník
- Department of Organic Chemistry
- Institute of Chemical Technology
- Prague, Czech Republic
| | - Radek Šachl
- Department of Biophysical Chemistry
- J. Heyrovsky Institute of Physical Chemistry
- Academy of Sciences of the Czech Republic
- 18223 Prague, Czech Republic
| | - Tereza Prausová
- Department of Organic Chemistry
- Institute of Chemical Technology
- Prague, Czech Republic
| | - Martin Hof
- Department of Biophysical Chemistry
- J. Heyrovsky Institute of Physical Chemistry
- Academy of Sciences of the Czech Republic
- 18223 Prague, Czech Republic
| | - Václav Kozmík
- Department of Organic Chemistry
- Institute of Chemical Technology
- Prague, Czech Republic
| | - Filip Teplý
- Institute of Organic Chemistry and Biochemistry
- Academy of Sciences of the Czech Republic
- 18223 Prague, Czech Republic
| | - Jiří Svoboda
- Department of Organic Chemistry
- Institute of Chemical Technology
- Prague, Czech Republic
| | - Marek Cebecauer
- Department of Biophysical Chemistry
- J. Heyrovsky Institute of Physical Chemistry
- Academy of Sciences of the Czech Republic
- 18223 Prague, Czech Republic
| |
Collapse
|
18
|
Boldyrev IA, Brown RE, Molotkovsky JG. An Expedient Synthesis of Fluorescent Labeled Ceramide-1-phosphate Analogues. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2013; 39:539-542. [PMID: 27429541 PMCID: PMC4943763 DOI: 10.1134/s106816201305004x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A synthesis for fluorescent analogs of ceramide-1-phosphate bearing 9-anthrylvinyl or 4,4-difluoro-3a,4a-diaza-s-indacene-8-yl (Me4-BODIPY) fluorophore at co-position of fatty acid residue was carried out. The key stage of the synthesis is hydrolysis of corresponding sphingomyelins catalyzed by phospholipase D from Streptomyces chromofuscus; the enzymatic yield has been raised to 50-70% by appliance of organic solvent in the incubation medium.
Collapse
Affiliation(s)
- I. A. Boldyrev
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997 Russian
| | - R. E. Brown
- Hormel Institute, University of Minnesota, Austin, MN 55912 USA
| | - J. G. Molotkovsky
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997 Russian
| |
Collapse
|
19
|
Motegi T, Nabika H, Murakoshi K. Single-molecule observations for determining the orientation and diffusivity of dye molecules in lipid bilayers. Phys Chem Chem Phys 2013; 15:12895-902. [PMID: 23812281 DOI: 10.1039/c3cp51585k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The molecular orientation and diffusion of dye molecules in artificial lipid bilayers were observed using total internal reflection fluorescence microscopy. An artificial lipid bilayer composed of a ternary lipid mixture of 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC), 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), and cholesterol was used. The molecular orientation, which was obtained through defocused imaging, clarified the microscopic features, including cholesterol-induced changes in the local packing structure. Diffusion analysis gave insights into the macroscopic aspects of phase distribution in the heterogeneous bilayer system. Combining these two independent investigations, we revealed the effect of cholesterol addition on microscopic local packing and macroscopic phase structures. Our observations showed a transition from a DLPC-network-like structure to a DPPC-network-like structure upon the addition of cholesterol, which was not evident from previous domain shape observations. The present single-molecule observations yielded the actual phase structure that controls the motion of molecules in the membrane. The results imply that the orientation and diffusivity of molecules offer useful information regarding the phase distribution, which may be hindered by the apparent phase structure in a heterogeneous lipid bilayer that contains cholesterol.
Collapse
Affiliation(s)
- Toshinori Motegi
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | | | | |
Collapse
|
20
|
Zhai X, Momsen WE, Malakhov DA, Boldyrev IA, Momsen MM, Molotkovsky JG, Brockman HL, Brown RE. GLTP-fold interaction with planar phosphatidylcholine surfaces is synergistically stimulated by phosphatidic acid and phosphatidylethanolamine. J Lipid Res 2013; 54:1103-13. [PMID: 23369752 DOI: 10.1194/jlr.m034744] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Among amphitropic proteins, human glycolipid transfer protein (GLTP) forms a structurally-unique fold that translocates on/off membranes to specifically transfer glycolipids. Phosphatidylcholine (PC) bilayers with curvature-induced packing stress stimulate much faster glycolipid intervesicular transfer than nonstressed PC bilayers raising questions about planar cytosol-facing biomembranes being viable sites for GLTP interaction. Herein, GLTP-mediated desorption kinetics of fluorescent glycolipid (tetramethyl-boron dipyrromethene (BODIPY)-label) from lipid monolayers are assessed using a novel microfluidics-based surface balance that monitors lipid lateral packing while simultaneously acquiring surface fluorescence data. At biomembrane-like packing (30-35 mN/m), GLTP uptake of BODIPY-glycolipid from POPC monolayers was nearly nonexistent but could be induced by reducing surface pressure to mirror packing in curvature-stressed bilayers. In contrast, 1-palmitoyl-2-oleoyl-phosphatidylethanolamine (POPE) matrices supported robust BODIPY-glycolipid uptake by GLTP at both high and low surface pressures. Unexpectedly, negatively-charged cytosol-facing lipids, i.e., phosphatidic acid and phosphatidylserine, also supported BODIPY-glycolipid uptake by GLTP at high surface pressure. Remarkably, including both 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate (5 mol%) and POPE (15 mol%) in POPC synergistically activated GLTP at high surface pressure. Our study shows that matrix lipid headgroup composition, rather than molecular packing per se, is a key regulator of GLTP-fold function while demonstrating the novel capabilities of the microfluidics-based film balance for investigating protein-membrane interfacial interactions.
Collapse
Affiliation(s)
- Xiuhong Zhai
- The Hormel Institute, University of Minnesota, Austin, MN, USA
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Armendariz KP, Huckabay HA, Livanec PW, Dunn RC. Single molecule probes of membrane structure: orientation of BODIPY probes in DPPC as a function of probe structure. Analyst 2012; 137:1402-8. [PMID: 22322157 DOI: 10.1039/c2an16255e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Single molecule fluorescence measurements have recently been used to probe the orientation of fluorescent lipid analogs doped into lipid films at trace levels. Using defocused polarized total internal reflection fluorescence microscopy (PTIRF-M), these studies have shown that fluorophore orientation responds to changes in membrane surface pressure and composition, providing a molecular level marker of membrane structure. Here we extend those studies by characterizing the single molecule orientations of six related BODIPY probes doped into monolayers of DPPC. Langmuir-Blodgett monolayers transferred at various surface pressures are used to compare the response from fluorescent lipid analogs in which the location of the BODIPY probe is varied along the length of the acyl chain. For each BODIPY probe location along the chain, comparisons are made between analogs containing phosphocholine and smaller fatty acid headgroups. Together these studies show a general propensity of the BODIPY analogs to insert into membranes with the BODIPY probe aligned along the acyl chains or looped back to interact with the headgroups. For all BODIPY probes studied, a bimodal orientation distribution is observed which is sensitive to surface pressure, with the population of BODIPY probes aligned along the acyl chains increasing with elevated surface pressure. Trends in the single molecule orientations for the six analogs reveal a configuration where optimal placement of the BODIPY probe within the acyl chain maximizes its sensitivity to the surrounding membrane structure. These results are discussed in terms of balancing the effects of headgroup association with acyl chain length in designing the optimal placement of the BODIPY probe.
Collapse
Affiliation(s)
- Kevin P Armendariz
- Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, KS 66047, USA
| | | | | | | |
Collapse
|
22
|
Huckabay HA, Dunn RC. Hydration effects on membrane structure probed by single molecule orientations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:2658-2666. [PMID: 21319764 DOI: 10.1021/la104792w] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Single molecule fluorescence measurements are used to probe the structural changes in glass-supported DPPC bilayers as a function of relative humidity (RH). Defocused polarized total internal reflection fluorescence microscopy is employed to determine the three-dimensional orientation of the fluorescent lipid analogue BODIPY-PC, doped into DPPC membranes in trace amounts. Supported DPPC bilayers formed using vesicle fusion and Langmuir-Blodgett/Langmuir-Schäfer (LB/LS) transfer are compared and show similar trends as a function of relative humidity. Population histograms of the emission dipole tilt angle reveal bimodal distributions as observed previously for BODIPY-PC in DPPC. These distributions are dominated by large populations of BODIPY-PC molecules with emission dipoles oriented parallel (≥81°) and normal (≤10°) to the membrane plane, with less than 25% oriented at intermediate tilts. As the relative humidity is increased from 13% to 95%, the population of molecules oriented normal to the surface decreases with a concomitant increase in those oriented parallel to the surface. The close agreement in trends observed for bilayers formed from vesicle fusion and LB/LS transfer supports the assignment of an equivalent surface pressure of 23 mN/m for bilayers formed from vesicle fusion. At each RH condition, a small population of BODIPY-PC dye molecules are laterally mobile in both bilayer preparations. This population exponentially increases with RH but never exceeds 6% of the total population. Interestingly, even under conditions where there is little lateral diffusion, fluctuations in the single molecule orientations can be observed which suggests there is appreciable freedom in the acyl chain region. Dynamic measurements of single molecule orientation changes, therefore, provide a new view into membrane properties at the single molecule level.
Collapse
Affiliation(s)
- Heath A Huckabay
- Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas , 2030 Becker Drive, Lawrence, Kansas 66047, United States
| | | |
Collapse
|
23
|
Šachl R, Rosenbaum E, Sellstedt M, Almqvist F, Johansson LBÅ. Locations and reorientations of multi-ring-fused 2-pyridones in ganglioside G(M1) micelles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:1662-1667. [PMID: 21210677 DOI: 10.1021/la104051z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Fluorescent multi-ring-fused 2-pyridones, with chemical resemblance to other biologically active 2-pyridone systems, were solubilized in spherical micelles formed by the ganglioside G(M1) and studied with respect to their spatial localization and rotational mobility. For this, electronic energy transfer between the multi-ring-fused 2-pyridone (donor) and BODIPY-FL-labeled G(M1) was determined, as well as their fluorescence depolarization. From the obtained efficiency of energy transfer to the acceptor group (BODIPY-FL), either localized in the polar or in the nonpolar part of the ganglioside, it has been possible to estimate the most likely localization of the multi-ring-fused 2-pyridones. The center of mass of the studied multi-ring-fused 2-pyridones are located at approximately 33 Å from the micellar center of mass, which corresponds to the internal hydrophobic-hydrophilic interfacial region. At this location, the reorienting rates of the multi-ring-fused 2-pyridones are surprisingly slow with typical correlation times of 35-55 ns. No evidence was found for the formation of ground and excited state dimers, even when two monomers were forced to be near each other via a short covalent linker.
Collapse
Affiliation(s)
- Radek Šachl
- Department of Chemistry, Umeå University, SE-90 187 Umeå, Sweden
| | | | | | | | | |
Collapse
|
24
|
Šachl R, Mikhalyov I, Gretskaya N, Olżyńska A, Hof M, Johansson LBÅ. Distribution of BODIPY-labelled phosphatidylethanolamines in lipid bilayers exhibiting different curvatures. Phys Chem Chem Phys 2011; 13:11694-701. [DOI: 10.1039/c1cp20608g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
25
|
Beranova L, Cwiklik L, Jurkiewicz P, Hof M, Jungwirth P. Oxidation changes physical properties of phospholipid bilayers: fluorescence spectroscopy and molecular simulations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:6140-4. [PMID: 20387820 DOI: 10.1021/la100657a] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Physical properties of oxidized phospholipid (OxPL) membranes consisting of binary mixtures of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 10 mol % of one of two OxPLs, 1-palmitoyl-2-glutaryl-sn-glycero-3-phosphocholine (PGPC) or 1-palmitoyl-2-(5'-oxo-valeroyl)-sn-glycero-3-phosphocholine (POVPC), were investigated experimentally and computationally. Fluorescence solvent relaxation (SR) and fluorescence correlation spectroscopy z-scan (FCS z-scan) show increased headgroup hydration and mobility, and faster lateral diffusion in POPC membrane upon addition of OxPLs. The magnitudes of both effects are distinct for each of the two OxPLs. Molecular dynamics simulations corroborate the experimental findings, providing at the same time a detailed molecular interpretation in terms of changes in bilayer structure and phospholipid orientation.
Collapse
Affiliation(s)
- Lenka Beranova
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, v. v. i., Dolejskova 3, 18223 Prague 8, Czech Republic
| | | | | | | | | |
Collapse
|