Self-Assembly of Condensed Biomolecular Phases

这项工作集中在一般生物分子自组装系统中的相行为，结构和控制相互作用，其中带电生物聚合物的凝聚排列是通过与不同复杂性的相反带电的微离子或宏离子相互作用形成的。直观地说，水溶液中两个带同种电荷的物体会相互排斥。然而，在多价大离子或微离子存在的情况下，许多生物聚合物可以相互吸引并凝聚成紧凑有序的状态。例子包括染色体中带电组蛋白的DNA凝聚和肌动蛋白细胞骨架的等级组织。这种吸引力的起源目前还不太清楚。该项目旨在描述负责这些复杂分子组织的物理机制。已经提出了各种形式的反离子相关作为观测到的异常吸引的可能机制。这些想法将首次得到验证，同时将使用同步加速器x射线散射、荧光显微镜和电子显微镜对整体生物聚合物相行为进行调查。这些熵调制的静电相互作用将被用于开发具有广泛应用的新型自组装系统，包括药物或基因递送载体、蛋白质结晶模板和生物传感器。这项工作的多学科性质将为这一新兴领域所需的新型混合科学家提供独特的教育机会。学生将为学术界、工业界或政府的一系列职业做好准备这项工作的方向是研究一类生物分子自组装材料的结构和控制相互作用，其中带电生物聚合物的凝聚排列是通过与不同复杂性的反向带电微离子或宏离子的相互作用形成的。直观地说，水溶液中两个带同种电荷的物体会相互排斥。然而，在多价大离子或微离子存在的情况下，许多生物聚合物可以相互吸引并凝聚成紧密有序的状态。例子包括染色体中带电蛋白的DNA凝聚和肌动蛋白细胞骨架的等级组织。这种吸引力的起源最近一直是激烈的理论辩论的主题，但没有达成共识。此外，没有定量的经验证据来区分许多建议的解释。使用一系列先进的实验技术，包括同步加速器x射线散射，荧光显微镜和电子显微镜，该计划旨在描述负责形成这些复杂的自组装生物分子系统的物理机制，并开发基于其新颖控制相互作用的新材料。这些材料系统具有广泛的应用，包括药物或基因传递系统，蛋白质结晶模板，中间生物传感器。这项工作的多学科性质将为这一新兴领域所需的新型混合科学家提供独特的教育机会。学生将为学术界、工业界或政府的一系列职业做好准备。

This work is centered on the phase behavior, structure and governing interactions in a general class of biomolecular self-assembled systems, where condensed arrangements of charged biopolymers are formed through their interactions with oppositely charged micro-ions or macro-ions of varying complexity. Intuitively, two like-charged objects in aqueous solution are expected to repel one another. .In the presence of multivalent macro-ions or micro-ions, however, many biopolymers can attract one another and condense into compact ordered states. Examples include DNA condensation by charged histone proteins in chromosome: and the hierarchical organization of the actin cytoskeleton. The origin of this attraction is at present poorly understood. This project aims to delineate the physical mechanisms responsible for these complex molecular organizations. Various forms of counterion correlations have been proposed as possible mechanisms for the observed anomalous attraction. These ideas will be tested for tile first time, along with an investigation of the global biopolymer phase behavior, using a combination of synchrotron x-ray scattering, epifluorescence microscopy, and electron microscopy. These entropically modulated electrostatic interactions will be exploited to develop new self-assembled Systems with a wide range of applications, including drug or gene delivery vehicles, templates for protein crystallization, and biosensors. The multi-disciplinary nature of this work will provide unique educational opportunities for the new kind of hybrid scientists necessary in this emerging field. The students will be prepared for a range of careers in academia, industry, or government %%%This work is directed at the structure and governing interactions of a general class of biomolecular self-assembled materials, where condensed arrangements of charged biological polymers are formed through their interactions with oppositely charged micro-ions or macro-ions of varying complexity. Intuitively, two like-charged objects in aqueous solution are expected to repel one another. In the presence of multivalent macro-ions or micro-ions, however, many biological polymers can attract one another and condense into compact ordered states. Examples include DNA condensation by charged proteins in chromosomes and the hierarchical organization of the actin cytoskeleton. The origin of this attraction has been the recent subject of intense theoretical debate, but no consensus has emerged. Further, there exists no quantitative empirical evidence to discriminate among the many suggested explanations. Using a range of advanced experimental techniques, including synchrotron x-ray scattering, fluorescence microscopy, and electron microscopy, this program aims to delineate the physical mechanisms responsible for the formation of these complex self-assembled biomolecular systems, and to develop new materials based on their novel governing interactions. These material systems have a wide range of applications, including drug or gene delivery systems, templates for protein crystallization, mid biosensors. The multidisciplinary nature of this work will provide unique educational opportunities for the new kind of hybrid scientists required for this emerging field. The students will be prepared for a range of careers in academia, industry, or government.