期刊
JOURNAL OF MEMBRANE BIOLOGY
卷 -, 期 -, 页码 -出版社
SPRINGER
DOI: 10.1007/s00232-023-00288-8
关键词
Langmuir monolayer; Model membranes; DPPC; Lipid interactions
The effect of relative composition of ?-Oryzanol (?-Or) on the liquid expanded-liquid condensed phase coexistence region in a mixed Langmuir monolayer was studied. It was found that as the relative composition of ?-Or increases, the range of area per molecule over which the coexistence of liquid expanded (LE)-liquid condensed (LC) phases exists reduces. The analysis of the liquid condensed-liquid expanded coexistence region in the isotherms showed that the molecular lateral density-strain coupling increases with the increase in the mole fraction of ?-Or in the mixed monolayer.
We have studied the effect of relative composition of ?-Oryzanol (?-Or) on the liquid expanded-liquid condensed phase coexistence region in the mixed Langmuir monolayer of ?-Or and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) molecules at air-water interface. The surface manometry studies at a fixed temperature show that the mixture of ?-Or and DPPC forms a stable monolayer at air-water interface. As the relative composition of ?-Or increases the range of area per molecule over which the coexistence of liquid expanded (LE)-liquid condensed (LC) phases exists reduces. Although the LE-LC phase coexistence corresponds to the first-order phase transition, the slope of the surface pressure-area per molecule isotherm is non-zero. Earlier studies have attributed the non-zero slope in LE-LC phase coexistence region to the influence of the strain between the ordered LC phase and disordered LE phase. The effect of strain on the coexistence of LE-LC phases can be studied in terms of molecular density-strain coupling. Our analysis of the liquid condensed-liquid expanded coexistence region in the isotherms of mixed monolayers of DPPC and ?-Or shows that with the increase in the mole fraction of sterol in the mixed monolayer the molecular lateral density-strain coupling increases. However, at 0.6 mole fraction of ?-Or in the mixed monolayer the coupling decreases. This is corroborated by the observation of minimum Gibb's free energy of the mixed monolayer at this relative composition of ?-Or indicating better packing of molecules.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据