Developing Electroanalytical Methods for Enzymology Applications

在化学部（CHE）的化学测量成像（CMI）计划和CBET部的生物传感器计划的支持下，犹他州大学的Shelley Minteer教授正在开发新的电分析工具，用于研究酶，生物催化剂，这些酶在生命过程的化学中起着关键作用，但在生物技术中也非常有用。 生物化学家和分子生物学家对酶的结构如何控制功能有着浓厚的兴趣。此外，酶激发了选择性催化剂的设计，用于具有挑战性的转化，例如将二氧化碳还原为甲醇和将氮气（N2）还原为氨。在过去的几十年里，这些属性激发了广泛的酶学研究，促进了人们对开发更好的分析工具来研究酶功能的兴趣。Minteer集团正在开发这些工具，并通过向大学生和高中生提供教育机会来扩大其影响。 例如，Minteer教授正在提供独特的高中学生研究实习机会，以激发学生对STEM（科学，技术，工程和数学）学科的兴趣。为了开发新的酶学电分析方法，关键是能够将酶以一种方式固定在电极表面上，从而它们可以与电极进行直接电子转移，而不需要外源性氧化还原介体。Minteer小组正在利用两种策略来实现直接电子转移：1）掺入非天然氨基酸作为蛋白质与电极表面缀合的定向标签，从而确保活性位点在电极表面的隧道距离内;和2）通过掺入金属结合肽序列将酶“连接”到电极表面，在蛋白质内原位形成金属纳米颗粒。通过任一方法修饰的生物电极将用于使用新的恒电流滴定方法研究单酶和酶级联，目的是更好地理解电子注入蛋白质（即固氮酶）活性位点的速率如何控制所形成的产物的选择性（氨与氢）。此外，旋转环盘电分析化学方法正在开发中，以研究基板通道和定量泄漏的中间体的散装解决方案，从超复杂的酶cascades.This奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用该基金会的智力价值和更广泛的影响审查标准。

With support from the Chemical Measurement & Imaging (CMI) program in the Division of Chemistry (CHE) and the Biosensors program in the CBET Division, Professor Shelley Minteer at the University of Utah is developing new electroanalytical tools for investigating enzymes, biological catalysts that play critical roles in the chemistry of life processes but that are also very useful in biotechnology. Biochemists and molecular biologists have keen interest in how enzyme structure controls function. In addition, enzymes have inspired the design of selective catalysts for challenging transformations such as reduction of carbon dioxide to methanol and nitrogen (N2) to ammonia. These attributes have motivated extensive enzymology research over the last couple of decades, prompting interest in developing better analytical tools for investigating enzyme function. The Minteer group is both developing such tools and extending their impact through educational opportunities offered to both college and high school students. For example, Professor Minteer is providing unique high school student research internships to inspire student interest in STEM (science, technology, engineering and mathematics) disciplines. In order to develop new electroanalytical methods for enzymology, it is critical to be able to immobilize enzymes on electrode surfaces in a manner whereby they can undergo direct electron transfer with the electrode without the need for exogenous redox mediators. The Minteer group is utilizing two strategies to enable direct electron transfer: 1) incorporation of non-natural amino acids as orienting tags for conjugation of proteins to electrode surfaces, thereby ensuring that the active site is within tunneling distance of the electrode surface; and 2) "wiring" enzymes to electrode surfaces by incorporating metal-binding peptide sequences that promote in-situ formation of metal nanoparticles within the protein. Bioelectrodes modified by either approach will be used to study both single enzymes and enzyme cascades using new galvanostatic titration methods, with an aim of improved understanding of how the rate of electron injection into the active site of a protein (i.e. nitrogenase) controls the selectivity of the products formed (ammonia versus hydrogen). Additionally, rotating ring-disk electroanalytical chemistry methods are being developed to study substrate channeling and to quantitate the leaking of intermediates to the bulk solution from the supercomplex of an enzyme cascade.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.