CAREER: Mechanism of Metallic Conductivity in Bacterial Pili Filaments

职业：细菌菌毛丝中金属导电性的机制

• 批准号: 1749662
• 负责人: Nikhil Malvankar
• 金额: $ 80万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-05-01 至 2023-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1749662&HistoricalAwards=false
• 关键词: CAREER; Mechanism; Metallic; Conductivity; Bacterial

The movement of electrons in biomolecules and materials is central to many physical, chemical and biological processes as well as to electronics industry. The PI has found that protein filaments of common soil bacteria can move electrons similar to metallic systems. In this CAREER Project, the PI will identify the mechanism underlying this process that occurs over unprecedented distances. The results of the research could have applications in environmental, bioenergy, and microelectronics applications. The PI will integrate this research into a range of educational activities that will inspire and train the next-generation of interdisciplinary students to tackle challenging problems. The PI will draw from his own training in biophysics and structural and molecular biology as well as his experience in technology innovation and entrepreneurship to reach students at all levels. Specifically, the PI will first develop a new cross-disciplinary curriculum for undergraduate and graduate students to introduce key concepts at the intersection of physics, chemistry and biology that are not covered in traditional courses. Second, the PI will design hands-on laboratory activity on the science of bacteria-powered fuel cells, using the feedback from the teachers of New Haven Public School that primarily serve minority students. Third, the PI will disseminate molecular structures through a user-friendly software based on First Glance and Proteopedia. Fourth, the PI will increase participation of underrepresented and minority students into research by working closely with the Yale assistant dean of science education and the coordinator for local community and outreach events. Thus, this CAREER project will integrate highly interdisciplinary research at the interfaces of physics, chemistry and biology with a diverse educational program reaching students at all levels.Electron transfer is fundamental to many life processes. Existing models of biological electron transfer rely primarily on tunneling and hopping mechanisms that are limited to few nanometers, and metallic conductivity has been considered impossible in proteins. These models cannot explain the remarkable capacity by bacteria to transport electrons over centimeters, 10,000 times their size. By introducing a new concept of delocalized conduction via closely stacked aromatic residues that can account for high conductivity in pili proteins, this CAREER project at Yale University proposal will expand the intellectual range of biophysics by building a mechanistic framework for extracellular electron transport. The overall goal of this project is to identify the mechanism of extracellular electron transfer in soil bacteria that occurs at rates and distances unprecedented in biology. Building on the discovery by the PI that pili protein filaments of Geobacter sulfurreducens show electrical properties similar to metallic polymers, this project aims to identify the structural, molecular and biophysical mechanism of metallic conductivity. First, the PI will identify crucial microscopic transport parameters in pili that led to electron delocalization. Second, the PI will visualize conformational changes in pili that drive electron transport. Third, the PI will obtain near atomic-resolution structures of pili using Cryo-EM. The success of this project could provide unprecedented new insights into the metabolism and communication of a diversity of microbial species that regulate our environment and are important for bioenergy and biofuel strategies. Engineering microbial interactions via conductive pili could potentially offer control over their physiology and ecology.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.

电子在生物分子和材料中的运动是许多物理、化学和生物过程以及电子工业的核心。PI发现，常见土壤细菌的蛋白质细丝可以移动电子，类似于金属系统。在这个职业项目中，PI将确定这一过程背后的机制，这一过程发生在前所未有的距离上。这项研究的结果可能会在环境、生物能源和微电子应用中得到应用。PI将把这项研究整合到一系列教育活动中，以激励和培训下一代跨学科学生解决具有挑战性的问题。PI将利用他自己在生物物理学和结构和分子生物学方面的培训以及他在技术创新和创业方面的经验，接触到所有级别的学生。具体地说，PI将首先为本科生和研究生开发一个新的跨学科课程，介绍传统课程中没有涵盖的物理、化学和生物交叉学科的关键概念。其次，PI将利用纽黑文公立学校教师的反馈，设计以细菌为动力的燃料电池科学的动手实验室活动，这些学校主要服务于少数族裔学生。第三，PI将通过基于First Glance和Proteopedia的用户友好软件来传播分子结构。第四，PI将通过与耶鲁大学科学教育助理院长以及当地社区和外联活动协调员密切合作，增加未被充分代表的学生和少数族裔学生参与研究。因此，这个职业项目将把物理、化学和生物界面的高度跨学科研究与多样化的教育计划结合起来，惠及所有层次的学生。电子转移是许多生命过程的基础。现有的生物电子转移模型主要依赖于限于几个纳米的隧道和跳跃机制，而金属导电性在蛋白质中被认为是不可能的。这些模型无法解释细菌传输超过厘米的电子的非凡能力，电子的大小是细菌的1万倍。通过引入一个新的概念，通过紧密堆积的芳香族残基进行离域传导，可以解释菌毛蛋白质的高电导率，耶鲁大学的这个职业项目提案将通过建立细胞外电子传输的机械框架来扩大生物物理学的智能范围。这个项目的总体目标是确定土壤细菌中细胞外电子转移的机制，这种转移发生的速度和距离在生物学上是前所未有的。在PI发现硫还原地杆菌菌毛蛋白细丝具有与金属聚合物相似的电学性质的基础上，本项目旨在确定金属电导率的结构、分子和生物物理机制。首先，PI将确定导致电子离域的菌毛中关键的微观传输参数。其次，PI将可视化菌毛中驱动电子传输的构象变化。第三，PI将利用低温电子显微镜获得近原子分辨的菌毛结构。该项目的成功可以为调节我们的环境的各种微生物物种的新陈代谢和交流提供前所未有的新见解，这些微生物物种对生物能源和生物燃料战略非常重要。通过传导性菌毛进行微生物相互作用工程可能提供对其生理和生态的控制。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Direct observation of anisotropic growth of water films on minerals driven by defects and surface tension

• DOI: 10.1126/sciadv.aaz9708
• 发表时间: 2020-07
• 期刊: Science Advances
• 影响因子: 13.6
• 作者: S. Yalcin;B. Legg;M. Yeşilbaş;N. Malvankar;J. Boily

Electric field stimulates production of highly conductive microbial OmcZ nanowires.

• DOI: 10.1038/s41589-020-0623-9
• 发表时间: 2020-10
• 期刊: Nature chemical biology
• 影响因子: 14.8
• 作者: Yalcin SE;O'Brien JP;Gu Y;Reiss K;Yi SM;Jain R;Srikanth V;Dahl PJ;Huynh W;Vu D;Acharya A;Chaudhuri S;Varga T;Batista VS;Malvankar NS
• 通讯作者: Malvankar NS

Structure of Microbial Nanowires Reveals Stacked Hemes that Transport Electrons over Micrometers

• DOI: 10.1016/j.cell.2019.03.029
• 发表时间: 2019-04-04
• 期刊: CELL
• 影响因子: 64.5
• 作者: Wang, Fengbin;Gu, Yangqi;Malvankar, Nikhil S.
• 通讯作者: Malvankar, Nikhil S.

Heme Hopping Falls Short: What Explains Anti-Arrhenius Conductivity in a Multi-heme Cytochrome Nanowire?

• DOI: 10.1101/2022.08.01.502099
• 发表时间: 2022-08
• 期刊: bioRxiv
• 作者: Matthew J. Guberman‐Pfeffer

Intrinsic electronic conductivity of individual atomically resolved amyloid crystals reveals micrometer-long hole hopping via tyrosines

• DOI: 10.1073/pnas.2014139118
• 发表时间: 2021-01-12
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Shipps, Catharine;Kelly, H. Ray;Malvankar, Nikhil S.
• 通讯作者: Malvankar, Nikhil S.