CAREER: The protein-mineral bond

职业：蛋白质与矿物质的结合

• 批准号: 0745808
• 负责人: Steven Lower
• 金额: $ 45.27万
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2014-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0745808&HistoricalAwards=false
• 关键词: CAREER; protein; mineral; bond

EAR-0745808LOWER, Stephen K.Forces are invisible yet their presence can be felt anywhere. For large organisms, like humans, the force of gravity exerts a controlling influence on our lives. For smaller organisms, like bacteria, gravity is a trivial force. Rather, intermolecular forces control the world of microbes. This CAREER proposal will explore forces at a range of spatial scales, from binding forces at the peptide-mineral interface to the gravitational attraction that exists between humans and celestial objects. The research portion of this proposal will focus on measuring the energy landscapes of putative mineral-binding proteins and peptides. This will be accomplished by using atomic force microscopy (AFM) to examine the relationship between the transition force (i.e. rupture force) and the rate at which the force is applied to a particular protein-mineral pair. Proteins specimens will include putative mineral-binding proteins (MtrC and OmcA) from the metal reducing bacterium Shewanella oneidensis, as well as phage that express peptides with putative mineral-binding motifs, and artificial membranes doped with mineral-binding proteins. Mineral specimens will include crystalline, thin films of hematite (Fe2O3), goethite (FeOOH), pyrolusite (MnO2), and manganite (MnOOH). Molecular simulations will be used to determine the theoretical stability of putative mineral-binding motifs and the affinity of particular peptides towards specific mineral phases. This proposed work will (1) determine fundamental kinetic and thermodynamic properties such as, the free energy of dissociation, the rate of dissociation, and the distance to the transition barrier, for each peptide-mineral pair (e.g., MtrC-hematite); (2) define the mineral substrate(s) for each protein (MtrC and OmcA) based on fundamental binding elements; (3) define the boundaries of mineral-binding domains within the primary sequences of MtrC and OmcA; (4) determine whether putative mineral-binding domains within MtrC or OmcA are similar or dissimilar to mineral-binding motifs evolved by phage; (5) compare the measured kinetic/thermodynamic data to values predicted by molecular simulations of peptide-mineral bonds; (6) use the binding force-signature of MtrC and OmcA to create affinity maps that show the location of specific proteins on the surface of living cells. Broader impact One of the great strengths of Geological/Earth Science is the breadth of time and space that are encompassed by this discipline. This proposal describes an educational outreach program that teaches students from elementary to graduate school about forces that exist from the nanometer length-scale (e.g., intermolecular forces) to the infinite (e.g., the gravitational force). Students who participate in the proposed outreach programs will come away with a much stronger appreciation of the fundamental forces within our universe and their impact on living organisms. The educational outreach portion of this proposal will create a lecture series on "Forces in Natur" and a complementary lab related to subsurface transport of bacteria. This lecture and lab will be taught every year to about 1500 undergraduate students enrolled in a class called Planet Earth. Education majors enrolled in the Planet Earth class will, in turn, assist the PI as he conducts a one-week summer camp for elementary school students at one of the local, pubic schools. This camp will consist of hands-on experiments related to microbiology, polymers, and forces. On the final day of camp, the students will teach the "teachers", that is, the children will guide the parents/teachers through the same experiments the children performed earlier in the week. The education outreach plan also includes a proposed scientific "test of astrology" that will be run in the university newspaper, which is available to about 50,000 students. This test draws a novel comparison between the gravitational force and the idea that celestial objects exert a force of influence on our lives. Finally, this award will fund three students (two undergraduate and one graduate student) who will participate in the proposed research project described above.

斯蒂芬·K·罗沃：力量是无形的，但他们的存在在任何地方都能感觉到。对于像人类这样的大型生物来说，重力对我们的生活产生了控制性的影响。对于较小的生物体，如细菌，重力是一个微不足道的力量。相反，分子间的力量控制着微生物的世界。这个CAREER提案将探索一系列空间尺度上的力，从肽-矿物质界面的结合力到人类与天体之间存在的引力。该提案的研究部分将侧重于测量推定的矿物质结合蛋白质和肽的能量景观。这将通过使用原子力显微镜（AFM）来检查转变力（即破裂力）与力施加到特定蛋白质-矿物质对的速率之间的关系来实现。蛋白质标本将包括来自金属还原菌Shewanella oneidensis的推定的矿物质结合蛋白（MtrC和OmcA），以及表达具有推定的矿物质结合基序的肽的噬菌体，以及掺杂有矿物质结合蛋白的人工膜。矿物样品将包括赤铁矿（Fe 2 O3）、针铁矿（FeOOH）、软锰矿（MnO 2）和锰矿（MnOOH）的结晶薄膜。分子模拟将用于确定假定的矿物质结合基序的理论稳定性和特定肽对特定矿物质相的亲和力。这项拟议的工作将（1）确定基本的动力学和热力学性质，如解离自由能，解离速率和距离过渡势垒，为每个肽-矿物质对（例如，MTRC-赤铁矿）;（2）确定每种蛋白质的矿物质底物（3）确定MtrC和OmcA一级序列中矿物质结合结构域的边界;（4）确定MtrC或OmcA中推定的矿物质结合结构域与噬菌体进化的矿物质结合基序是否相似或不相似;（5）将测得的动力学/热力学数据与通过肽-矿物质键的分子模拟预测的值进行比较;（6）使用MtrC和OmcA的结合力签名来创建显示活细胞表面上特定蛋白质的位置的亲和图。地质/地球科学的最大优势之一是这门学科所涵盖的时间和空间的广度。该提案描述了一个教育推广计划，该计划向从小学到研究生院的学生讲授纳米长度尺度上存在的力（例如，分子间力）到无穷大（例如，重力）。参加拟议的外展计划的学生将对我们宇宙中的基本力量及其对生物体的影响有更强的认识。该提案的教育推广部分将创建一个关于“自然力量”的系列讲座和一个与细菌地下运输有关的补充实验室。该讲座和实验室每年将为大约1500名参加“地球”课程的本科生授课。在行星地球班就读的教育专业学生将反过来协助PI在当地的一所公立学校为小学生举办为期一周的夏令营。这个夏令营将包括与微生物学，聚合物和力相关的实践实验。在夏令营的最后一天，学生们将教“老师”，也就是说，孩子们将指导家长/老师通过同样的实验，孩子们在本周早些时候进行。教育推广计划还包括一项拟议中的科学“占星术测试”，该测试将在大学报纸上刊登，约有5万名学生可以阅读。这个测试在引力和天体对我们生活施加影响力的想法之间进行了一个新颖的比较。最后，该奖项将资助三名学生（两名本科生和一名研究生），他们将参加上述拟议的研究项目。