Electrostatic Roles on Macromolecular Assemblies in Vision Processes

非技术性总结看的能力是人类和他/她的宇宙的其他部分之间的接口。这种能力经常受到大分子及其组装体（构成人眼的几个部分）故障的阻碍。实例包括人透镜中的晶状体蛋白和人眼玻璃体中的透明质酸-胶原复合凝胶。尽管了解这些带电大分子在人眼中的行为具有巨大的意义，但缺乏基本的理解。挑战来自晶体蛋白质序列的变化以及它们如何通过疏水和静电相互作用的组合相互作用。在玻璃体的情况下，胶原分子如何在透明质酸基质产生的限制性凝胶样环境中组织成纤维，是定量和基础研究的新领域。主要研究者建议使用合成的组合，包括定点诱变和化学合成，计算机建模，使用光散射，显微镜和流变学的表征技术，以及先进的聚合物物理理论。所提出的研究的主要组成部分之一是指导和建立科学基础，为下一代科学家在摆脱人类失明的一个非常重要的领域进行基础研究。技术概述提出实验和建模来理解与人类透镜相关的晶状体蛋白的聚集/解聚，以及使用定点诱变、化学合成、静态和动态光散射、微分动态显微镜、流变学和计算机建模在与人玻璃体相关的透明质酸基质中组装胶原束。具体而言，该提案解决了（i）晶体蛋白蛋白质序列（通过定点诱变合成）对聚集的作用，（ii）晶体蛋白质的电荷修饰对聚集/解聚的作用，（iii）胶原束的成核和生长，以及（iv）透明质酸基质内胶原束的不均匀分布的程度。拟议的工作旨在确定大量蛋白质分子在水相拥挤环境中聚集的基本原理，基于构象波动和静电力的可控调制。所提出的体外实验将导致对人眼所需的透光性的大分子来源的见解。在这个跨学科领域培养学生，重点关注基本的理解是拟议活动的重要教育组成部分。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL SUMMARYThe ability to see is the interface between a human and the rest of his/her universe. This ability is often hampered by malfunctioning of macromolecules and their assemblies which make up several compartments of human eye. Examples include crystallin proteins in human lens and hyaluronic acid-collagen composite gel in the vitreous of human eye. Despite the enormous significance of knowing how these charged macromolecules behave in the human eye, a fundamental understanding is lacking. The challenge arises from variations in the sequences of the crystallin proteins and how they interact among themselves via a combination of hydrophobic and electrostatic interactions. In the case of vitreous, how the collagen molecules organize into fibers inside a restrictive gel-like environment created by hyaluronic acid matrix, is a new area for quantitative and fundamental investigation. The Principal Investigator proposes to use a combination of synthesis, including site-directed mutagenesis and chemical synthesis, computer modeling, characterization techniques using light scattering, microscopy, and rheology, and advanced polymer physics theories. One of the major components of the proposed research is to mentor and build scientific foundation for the next generation of scientists to pursue fundamental research in an area of tremendous importance in getting rid of human blindness.TECHNICAL SUMMARYExperiments and modeling are proposed to understand the aggregation/disaggregation of crystallin proteins pertinent to human lens, and the assembly of collagen bundles in hyaluronic acid matrixes pertinent to human vitreous, using site-directed mutageneis, chemical synthesis, static and dynamic light scattering, differential dynamic microscopy, rheology, and computer modeling. Specifically, the proposal addresses (i) role of crystallin protein sequences (synthesized by site-directed mutagenesis) on aggregation, (ii) role of charge modification of crystallin proteins on aggregation/disaggregation, (iii) nucleation and growth of collagen bundles, and (iv) extent of heterogeneous distribution of collagen bundles inside hyaluronic acid matrix. The proposed work aims at identifying fundamental principles behind aggregation of large numbers of protein molecules in aqueous crowded environments, based on conformational fluctuations and controllable modulations of electrostatic forces. The proposed in vitro experiments will result in insights on the macromolecular origins for required transparency to light in human eye. Training students in this interdisciplinary area with a strong focus on fundamental understanding is the strong educational component of the proposed activity.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.