RUI: Self-Assembled Interfaces: Protolipids, Asymmetry, and Energetics

艾奥纳大学化学系李成熙教授及其研究小组在化学系大分子、超分子和纳米化学项目的支持下，正在进行活细胞如何在其膜中排列分子组分的研究。这些边界层由长尾脂质（脂肪）分子组成，这些分子组装成双层（双层），内层相对于外层具有不同种类的脂质分子。这种分子差异或不对称性对细胞功能至关重要，但这种排列的根本原因尚不完全清楚。李教授和她的团队将探索细胞膜的脂质组成的大阵列，使用细胞大小的水滴，自我安排成不对称的双层，并在显微镜下检查这些细胞模拟物的物理，化学和机械性能。该项目的目标是确定单个脂质分子的不同形状和大小如何影响细胞膜的机械强度，泄漏和稳定性，这决定了活细胞的功能和生命周期。该项目有可能提供有助于软物质系统和功能材料设计的见解，并有助于更好地理解生物相关材料。 拟议工作的更广泛的科学影响涉及这些研究对生物传感器，诊断和药物筛选平台生产的潜在长期影响。该项目还将采用研究方法，通过假设驱动的跨学科研究，帮助培养下一代具有全球竞争力的科学家，预计将包括代表性不足的群体成员的参与。 本研究计划通过邀请初中生和少数民族服务机构的教师参与，扩大公众对本研究的参与。在该奖项下，李成熙教授及其团队将在对称和不对称的平面脂质双分子层上施加增加的自发曲率，并确定双分子层形成的驱动力的变化，以开发曲率弹性应力能的直接实验传感器。模型的对称和不对称的双层包括脂质的负曲率将检查其影响后，双层形成的热力学驱动力。为了量化脂质形状的影响，Lee小组将获得跨双层的水传输参数，确定双层稳定性参数，确定电特性，使用振动光谱法确定酰基链顺序，并对脂质分散体进行热致分析。该技术的传播将包括与合作者合作，将不对称液滴界面双层技术应用于蛋白质功能的研究。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Sunghee Lee and her research group in the Department of Chemistry at Iona University are undertaking studies on how living cells arrange molecular components in their membranes. These boundary layers are composed of long-tailed lipid (fatty) molecules that assemble in a double layer (a bilayer) with different kinds of lipid molecules on the inner layer relative to the outer layer. This molecular difference, or asymmetry, is vital for cell function, and yet the fundamental reasons for this arrangement are not fully known. Professor Lee and her team will explore a large array of lipid compositions of cell membranes, using cell-size water droplets that self-arrange into asymmetric bilayers, and microscopically examine the resulting physical, chemical, and mechanical properties of these cell-mimics. The goal of the project is to determine how the differing shapes and sizes of individual lipid molecules can impact cell-membrane mechanical strength, leakiness, and stability, which determine the functions and the life cycle of living cells. The project has the potential to provide insights that aid in the design of soft matter systems and functional materials, and also contribute to better understanding of biologically relevant materials. The scientific broader impacts of the proposed work relate to potential longer term implications of these studies for the production of biosensors, diagnostics, and drug screening platforms. This project will also employ research methods that will help train the next generation of globally-competitive scientists with hypothesis-driven interdisciplinary research, and is expected to include participation from members of underrepresented groups. Outreach activities are planned to extend the public engagement with this research by involving middle/high school students and teachers at minority serving institutions.Under this award, Professor Sunghee Lee and her group will impose increasing spontaneous curvature upon symmetric and asymmetric planar lipid bilayers and ascertain changes in the driving force for bilayer formation, to develop a direct experimental transducer for curvature elastic stress energy. Models of symmetric and asymmetric bilayers comprising lipids of negative curvature will be examined for their effect upon the thermodynamic driving force for bilayer formation. To quantify the effects of lipid shape, the Lee group will acquire water transport parameters across the bilayer, determine bilayer stability parameters, ascertain electrical properties, use vibrational spectroscopy for determination of acyl chain order, and perform thermotropic analyses of lipid dispersions. Dissemination of the technology will include working with collaborators to apply the techniques of asymmetric droplet interface bilayers for studies of protein function.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.