Academic Journal
Thermodynamic and Mechanical Properties of DMPC/Cholesterol Mixed Monolayers at Physiological Conditions
| العنوان: | Thermodynamic and Mechanical Properties of DMPC/Cholesterol Mixed Monolayers at Physiological Conditions |
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| المؤلفون: | Bañuelos-Frias, Alan, Castañeda-Montiel, Victor Manuel, Alvizo-Paez, Edgar Rogelio, Vazquez-Martinez, Emmanuel Antonio, Gomez, Eduardo, Ruiz-Garcia, Jaime |
| المساهمون: | Consejo Nacional de Ciencia y Tecnología |
| المصدر: | Frontiers in Physics ; volume 9 ; ISSN 2296-424X |
| بيانات النشر: | Frontiers Media SA |
| سنة النشر: | 2021 |
| المجموعة: | Frontiers (Publisher - via CrossRef) |
| الوصف: | One of the main known effects of cholesterol is to rigidify the cell membrane throughout the so-called condensing effect. Although many studies have been done in mixtures of cholesterol with different membrane lipids, there are not many studies in a wide concentration range of cholesterol or at physiological conditions. In this work, we studied mixtures of DMPC/Cholesterol monolayers to determine the effect of cholesterol, from very low to physiological concentrations and two pHs. We use a Langmuir balance and Brewster angle microscopy to study their thermodynamic behavior at 37.0 ± 0.1°C at the air/solution interface. From the analysis of the ( π− A) isotherms, we determined the excess area and the compressibility elastic modulus to determine the monolayers mechanical properties. Surprisingly, we found three main effects of cholesterol: The first one is a fluidization effect of the monolayer at all cholesterol concentrations. The second effect is the so-called condensing effect that appears due to the non-ideality of the mixture. The third effect is a stiffness of the monolayer as the cholesterol concentration increases. These effects are stronger in pure water, pH ≈ 6.6, than on buffer at physiological pH = 7.4. We also found that all mixtures are thermodynamically stable at all concentrations at a surface pressure of 30.1 ± 1.6 and 27.4 ± 3.2 mN/m in pure water and buffer, respectively. Furthermore, we compared this stability with a fatty acid monolayer that shows a much lower surface pressure equilibrium value that DMPC or its mixtures with cholesterol, indicating a possibly reason why double chain lipids are better than single chain lipids to made up the cell membrane. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | unknown |
| DOI: | 10.3389/fphy.2021.636149 |
| DOI: | 10.3389/fphy.2021.636149/full |
| الاتاحة: | http://dx.doi.org/10.3389/fphy.2021.636149 https://www.frontiersin.org/articles/10.3389/fphy.2021.636149/full |
| Rights: | https://creativecommons.org/licenses/by/4.0/ |
| رقم الانضمام: | edsbas.9D558D1F |
| قاعدة البيانات: | BASE |
| DOI: | 10.3389/fphy.2021.636149 |
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