当前位置: X-MOL 学术Langmuir › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Bridges of Calcium Bicarbonate Tightly Couple Dipolar Lipid Membranes.
Langmuir ( IF 3.7 ) Pub Date : 2020-08-12 , DOI: 10.1021/acs.langmuir.0c01511
Lea Fink 1 , Christoph Allolio 1, 2 , Jehuda Feitelson 1 , Carmen Tamburu 1 , Daniel Harries 1, 2 , Uri Raviv 1
Affiliation  

The interaction between lipid membranes and ions is associated with a range of key physiological processes. Most earlier studies have focused on the interaction of lipids with cations, while the specific effects of the anions have been largely overlooked. Owing to dissolved atmospheric carbon dioxide, bicarbonate is an important ubiquitous anion in aqueous media. In this paper, we report on the effect of bicarbonate anions on the interactions between dipolar lipid membranes in the presence of previously adsorbed calcium cations. Using a combination of solution X-ray scattering, osmotic stress, and molecular dynamics simulations, we followed the interactions between 1,2-didodecanoyl-sn-glycero-3-phosphocholine (DLPC) lipid membranes that were dialyzed against CaCl2 solutions in the presence and absence of bicarbonate anions. Calcium cations adsorbed onto DLPC membranes, charge them, and lead to their swelling. In the presence of bicarbonate anions, however, the calcium cations can tightly couple one dipolar DLPC membrane to the other and form a highly condensed and dehydrated lamellar phase with a repeat distance of 3.45 ± 0.02 nm. Similar tight condensation and dehydration has only been observed between charged membranes in the presence of multivalent counterions. Bridging between bilayers by calcium bicarbonate complexes induced this arrangement. Furthermore, in this condensed phase, lipid molecules and adsorbed ions were arranged in a two-dimensional oblique lattice.

中文翻译:


碳酸氢钙桥紧密耦合偶极脂质膜。



脂质膜和离子之间的相互作用与一系列关键的生理过程相关。大多数早期研究都集中在脂质与阳离子的相互作用上,而阴离子的具体作用在很大程度上被忽视了。由于溶解了大气中的二氧化碳,碳酸氢盐是水介质中普遍存在的重要阴离子。在本文中,我们报告了在先前吸附的钙阳离子存在的情况下碳酸氢根阴离子对偶极脂质膜之间相互作用的影响。结合溶液 X 射线散射、渗透应力和分子动力学模拟,我们跟踪了在 CaCl 2溶液中透析的 1,2-二十二酰基-sn-甘油-3-磷酸胆碱 (DLPC) 脂质膜之间的相互作用。碳酸氢根阴离子的存在和不存在。钙阳离子吸附在 DLPC 膜上,使膜带电并导致膜膨胀。然而,在碳酸氢根阴离子存在的情况下,钙阳离子可以将一个偶极 DLPC 膜与另一个偶极 DLPC 膜紧密耦合,并形成高度凝聚和脱水的层状相,重复距离为 3.45 ± 0.02 nm。仅在多价抗衡离子存在的情况下,在带电膜之间观察到类似的紧密缩合和脱水。碳酸氢钙复合物在双层之间桥接诱导了这种排列。此外,在该凝聚相中,脂质分子和吸附的离子排列成二维倾斜晶格。
更新日期:2020-09-15
down
wechat
bug