Cations Do Not Alter the Membrane Structure of POPC—A Lipid With an Intermediate Area
Combining small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), and densitometric measurements, we have studied the interactions of the divalent cations Ca2+ and Mg2+ with the lipid vesicles prepared of a mixed-chain palmitoyl-oleoyl-phosphatidylcholine (POPC) at 25°C. The stru...
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Frontiers Media S.A.
2022-07-01
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| Series: | Frontiers in Molecular Biosciences |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmolb.2022.926591/full |
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| author | Sergei Kurakin Sergei Kurakin Oleksandr Ivankov Vadim Skoi Vadim Skoi Alexander Kuklin Alexander Kuklin Daniela Uhríková Norbert Kučerka Norbert Kučerka |
| author_facet | Sergei Kurakin Sergei Kurakin Oleksandr Ivankov Vadim Skoi Vadim Skoi Alexander Kuklin Alexander Kuklin Daniela Uhríková Norbert Kučerka Norbert Kučerka |
| author_sort | Sergei Kurakin |
| collection | DOAJ |
| description | Combining small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), and densitometric measurements, we have studied the interactions of the divalent cations Ca2+ and Mg2+ with the lipid vesicles prepared of a mixed-chain palmitoyl-oleoyl-phosphatidylcholine (POPC) at 25°C. The structural parameters of the POPC bilayer, such as the bilayer thickness, lateral area, and volume per lipid, displayed no changes upon the ion addition at concentrations up to 30 mM and minor changes at > 30 mM Ca2+ and Mg2+, while some decrease in the vesicle radius was observed over the entire concentration range studied. This examination allows us to validate the concept of lipid–ion interactions governed by the area per lipid suggested previously and to propose the mixed mode of those interactions that emerge in the POPC vesicles. We speculate that the average area per POPC lipid that corresponds to the cutoff length of lipid–ion interactions generates an equal but opposite impact on ion bridges and separate lipid–ion pairs. As a result of the dynamic equilibrium, the overall structural properties of bilayers are not affected. As the molecular mechanism proposed is affected by the structural properties of a particular lipid, it might help us to understand the fundamentals of processes occurring in complex multicomponent membrane systems. |
| first_indexed | 2024-04-12T08:40:27Z |
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| institution | Directory Open Access Journal |
| issn | 2296-889X |
| language | English |
| last_indexed | 2024-04-12T08:40:27Z |
| publishDate | 2022-07-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Molecular Biosciences |
| spelling | doaj.art-2e7c096f34fc46758a0fbe37fbb13a7e2022-12-22T03:39:54ZengFrontiers Media S.A.Frontiers in Molecular Biosciences2296-889X2022-07-01910.3389/fmolb.2022.926591926591Cations Do Not Alter the Membrane Structure of POPC—A Lipid With an Intermediate AreaSergei Kurakin0Sergei Kurakin1Oleksandr Ivankov2Vadim Skoi3Vadim Skoi4Alexander Kuklin5Alexander Kuklin6Daniela Uhríková7Norbert Kučerka8Norbert Kučerka9Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, RussiaInstitute of Physics, Kazan Federal University, Kazan, RussiaFrank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, RussiaFrank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, RussiaMoscow Institute of Physics and Technology, Dolgoprudnyi, RussiaFrank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, RussiaMoscow Institute of Physics and Technology, Dolgoprudnyi, RussiaDepartment of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, Bratislava, SlovakiaFrank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, RussiaDepartment of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, Bratislava, SlovakiaCombining small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), and densitometric measurements, we have studied the interactions of the divalent cations Ca2+ and Mg2+ with the lipid vesicles prepared of a mixed-chain palmitoyl-oleoyl-phosphatidylcholine (POPC) at 25°C. The structural parameters of the POPC bilayer, such as the bilayer thickness, lateral area, and volume per lipid, displayed no changes upon the ion addition at concentrations up to 30 mM and minor changes at > 30 mM Ca2+ and Mg2+, while some decrease in the vesicle radius was observed over the entire concentration range studied. This examination allows us to validate the concept of lipid–ion interactions governed by the area per lipid suggested previously and to propose the mixed mode of those interactions that emerge in the POPC vesicles. We speculate that the average area per POPC lipid that corresponds to the cutoff length of lipid–ion interactions generates an equal but opposite impact on ion bridges and separate lipid–ion pairs. As a result of the dynamic equilibrium, the overall structural properties of bilayers are not affected. As the molecular mechanism proposed is affected by the structural properties of a particular lipid, it might help us to understand the fundamentals of processes occurring in complex multicomponent membrane systems.https://www.frontiersin.org/articles/10.3389/fmolb.2022.926591/fulllipid bilayerstructurecationsSAXSSANSdensitometry |
| spellingShingle | Sergei Kurakin Sergei Kurakin Oleksandr Ivankov Vadim Skoi Vadim Skoi Alexander Kuklin Alexander Kuklin Daniela Uhríková Norbert Kučerka Norbert Kučerka Cations Do Not Alter the Membrane Structure of POPC—A Lipid With an Intermediate Area Frontiers in Molecular Biosciences lipid bilayer structure cations SAXS SANS densitometry |
| title | Cations Do Not Alter the Membrane Structure of POPC—A Lipid With an Intermediate Area |
| title_full | Cations Do Not Alter the Membrane Structure of POPC—A Lipid With an Intermediate Area |
| title_fullStr | Cations Do Not Alter the Membrane Structure of POPC—A Lipid With an Intermediate Area |
| title_full_unstemmed | Cations Do Not Alter the Membrane Structure of POPC—A Lipid With an Intermediate Area |
| title_short | Cations Do Not Alter the Membrane Structure of POPC—A Lipid With an Intermediate Area |
| title_sort | cations do not alter the membrane structure of popc a lipid with an intermediate area |
| topic | lipid bilayer structure cations SAXS SANS densitometry |
| url | https://www.frontiersin.org/articles/10.3389/fmolb.2022.926591/full |
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