Mimicking the Nuclear Pore Complex with Protein Hydrogels

ID：MPS/DMR/BMAT（7623）0906843 PI：Baker，Lane ORG：印第安纳州大学名称：蛋白质水凝胶模拟核孔复合物的研究智能：核孔复合物（NPC）介导真核生物细胞核和细胞质之间的物质转运。目前的研究表明，这种独特的转运机制依赖于一种蛋白质基水凝胶，这种水凝胶具有高度选择性，能够抵抗浓度梯度。最近已经确定了NPC的一个良好分辨的结构模型。该模型和相关报道已经阐明了与通过NPC的转运机制相关的许多方面，但是这种选择性水凝胶相的关键特征尚不清楚。该提案的长期目标是了解管理这种蛋白质水凝胶操作的基本机制。PI还希望将这些知识转化为能够在离体平台中进行选择性分离和传感的合成生物材料。该建议的中心假设是，通过表达在NPC中发现的选定蛋白质并合理地突变这些表达蛋白质的结构，可以开发出通过NPC转运的分子机制的更好的图片。此外，假设这种增强的理解将允许开发将显示仿生运输性质的模型半合成多肽水凝胶。这一假设是基于文献报道和初步研究制定的，这些研究表明NPC蛋白质可以在离体环境中被迫形成选择性水凝胶。 具体而言，PI将：（1）确定位于核孔复合物内的蛋白质的相对相互作用和性质，所述蛋白质的相对相互作用和性质是再现在核孔复合物中观察到的选择性转运所必需的，（2）确定蛋白质水凝胶的亲水区域对转运的影响以及这些区域可用于合成地改变转运性质的程度，和（3）开发使用固相肽合成产生半合成水凝胶的途径。更广泛的意义：生物系统为合理的材料设计提供了非凡的洞察力和灵感。为了提高目前的能力，必须实现生物机制（如核质转运）的根本性进展。这项研究所依据的主题是什么？生物材料和生物/分析化学？可以用来吸引学生，特别是如果主题是以适当的方式处理。为此，PI发起了一项教育推广计划，该计划与研究计划的主题相结合，并涉及研究生参与该小组。该推广计划使用视觉学习概念和信息传播，使用视频会议与播客技术相协调，形成具体的模块，包括播客，课堂练习，后续现场视频会议和对练习的简短评估。最初，他们专注于与两所高中合作，其中一所主要为代表性不足的群体服务。这两所高中都位于数百英里（1300和800，分别）从PI？的实验室。这是为了证明正在开发的教育计划可以有效地利用互联网来弥合地理和人口方面的差距。为了增加该计划的影响，PI对合作学校进行了初步的个人访问，并在整个学期使用视频会议参加互动问答。沿着这一合作，额外的内容将被开发和传播在单独的播客，专门针对化学学生在高中，本科和研究生水平。还通过同行评审期刊传播工作成果。该计划的教学评估将与印第安纳州大学校园设施合作进行。

ID: MPS/DMR/BMAT(7623) 0906843 PI: Baker, Lane ORG: Indiana UniversityTitle: Mimicking the Nuclear Pore Complex with Protein HydrogelsINTELLECTUAL MERIT: The nuclear pore complex (NPC) mediates transport of materials between the nucleus and cytoplasm of eukaryotic organisms. Current research indicates this unique transport mechanism relies on a protein-based hydrogel, which is both highly selective and capable of operating against concentration gradients. A well-resolved structural model of the NPC has been recently determined. This model and related reports have elucidated many aspects related to the mechanism of transport through the NPC, however critical features of this selective hydrogel phase are not understood. The long term goal of the proposal is to understand the fundamental mechanisms that govern the operation of this protein-hydrogel. The PI would also like to translate this knowledge to synthetic-based biomaterials capable of performing selective separations and sensing in ex-vivo platforms. The central hypothesis of this proposal is that by expressing selected proteins found in the NPC and rationally mutating the structure of these expressed proteins, a better picture of the molecular mechanisms of transport through the NPC can be developed. Further, it is hypothesized that this enhanced understanding will allow development of model semi-synthetic polypeptide hydrogels that will display biomimetic transport properties. This hypothesis has been formulated based on literature reports and preliminary studies, which show proteins from the NPC can be coerced to form selective hydrogels in ex-vivo environments. Specifically, the PI will: (1) determine the relative interactions and properties of proteins located within the nuclear pore complex that are necessary to reproduce selective transport observed in the nuclear pore complex, (2) determine the influence of the hydrophilic regions of the protein hydrogel on transport and the extent to which these regions can be used to synthetically alter transport properties, and (3) develop a route for generating a semi-synthetic hydrogel using solid phase peptide synthesis. BROADER IMPACTS: Biological systems offer remarkable insight and inspiration for rational materials design. To advance current capabilities, fundamental advances in how biological mechanisms, such as nucleocytoplasmic transport, operate must be realized. The themes upon which this research is based ? biomaterials and bio/analytical chemistry ? can be used to engage students, especially if the subject matter is approached in an appropriate manner. To this end, the PI has initiated an educational outreach program that is integrated with the subject matter of the research program and involves the participation of graduate students in the group. The outreach program uses visual learning concepts and information dissemination using video conferencing in coordination with podcasting technology, forming specific modules that consist of a podcast, a classroom exercise, a follow-up live video conference, and a short assessment of the exercise. Initially, they are focusing on collaboration with two high schools, one of which serves predominantly underrepresented groups. Both high schools are located hundreds of miles (1300 and 800, respectively) from the PI?s laboratory. This is intended to prove that the educational program under development can use the internet effectively to bridge both geographic and demographic divides. To increase the impact of the program the PI makes initial personal visits to the collaborating schools and participates in interactive question-and answer sessions throughout the semester using video conferencing. Along with this collaboration, additional content will be developed and disseminated in separate podcasts that specifically target chemistry students at the high school, undergraduate, and graduate levels. Work is also disseminated through peer-reviewed journals. Pedagogical assessment of the program will be performed in collaboration with Indiana University campus facilities.