Šturcová Adriana
Department of Polymers for Electronics and Photonics, Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, Prague 6 162 00, Czech Republic.
J Phys Chem B. 2025 Feb 6;129(5):1563-1585. doi: 10.1021/acs.jpcb.4c05176. Epub 2025 Jan 24.
The structural response of 1,2-dimyristoyl-glycero-3-phosphatidylcholine (DMPC)/water bilayers to addition and subsequent solvation of a small amphiphilic molecule - an anesthetic benzyl alcohol - was studied by means of solid-state NMR (H NMR, P NMR) spectroscopy and low-angle X-ray diffraction. The sites of binding of this solute molecule within the bilayer were determined - the solute was shown to partition between several sites in the bilayer and the equilibrium was shown to be dynamic and dependent on the level of hydration and temperature. At the same time, it was shown that solubilization of benzyl alcohol reached a solubility limit and was terminated when the ordering profile of DMPC hydrocarbon chains adopted finite limiting values throughout the whole chain. Such findings were made probably for the first time for any lipid bilayer system and possibly have more general implications for dissolution of other small-molecule amphiphilic solutes in lipid bilayer systems other than DMPC. The limit to the hydrocarbon chain profile is probably a more general property and corresponds to the balance of intrabilayer and interbilayer forces established in combination with the elastic properties of the bilayer system that still consists of one single phase just before the solute forms an excess phase. It is not necessary to quantify the contribution of each individual intrabilayer and interbilayer force acting within such a bilayer system. A model of the dependence of surface density of lipid chains on the chain segment order parameter was also developed - an empirical mathematical model based on experimental data was derived and it was proposed to represent a relationship between intrinsic bilayer forces and bilayer deformation characteristics and might be proven to be of more general significance in the future.
通过固态核磁共振（氢核磁共振、磷核磁共振）光谱法和小角X射线衍射法，研究了1,2-二肉豆蔻酰-sn-甘油-3-磷酸胆碱（DMPC）/水双层膜对一种小分子两亲性分子——麻醉剂苯甲醇的添加及随后溶剂化的结构响应。确定了该溶质分子在双层膜内的结合位点——结果表明该溶质在双层膜的多个位点之间分配，且平衡是动态的，取决于水合水平和温度。同时，研究表明苯甲醇的增溶达到了溶解度极限，当DMPC烃链的有序分布在整个链上采用有限的极限值时增溶终止。对于任何脂质双层系统而言，这些发现可能是首次获得，并且可能对除DMPC之外的其他脂质双层系统中其他小分子两亲性溶质的溶解具有更普遍的意义。烃链分布的极限可能是一种更普遍的性质，它对应于双层膜内和双层膜间作用力的平衡，这种平衡是与双层膜系统的弹性性质相结合而建立的，就在溶质形成过量相之前，该双层膜系统仍由单一相组成。没有必要量化在这样一个双层膜系统中起作用的每个双层膜内和双层膜间作用力的贡献。还建立了一个脂质链表面密度与链段序参数之间依赖关系的模型——基于实验数据推导了一个经验数学模型，并提出该模型代表了内在双层膜作用力与双层膜变形特征之间的关系，未来可能被证明具有更普遍的意义。
