CAREER: Discovering and Engineering Protein-Based Sensors for Nitrate in Biology

在化学学部生命过程化学项目的支持下，来自达拉斯德克萨斯大学的Sheel C. Dodani将研究硝酸盐氧阴离子的生物化学。人们普遍认为，硝酸盐是细菌和植物呼吸、生长和信号传递等基本功能所必需的。然而，关于硝酸盐对人体的有益和有害影响，仍有许多未知之处。为了填补这一知识空白，Dodani实验室将研究和设计蛋白质传感器，努力开发硝酸盐选择性传感器。如果成功的话，这种蛋白质有可能检测活细胞中的硝酸盐，并且，从长远来看，阐明硝酸盐的生化作用。这些努力将与一项教育计划相结合，该计划旨在通过为本科生开发一门名为“厨房里的Hofmeister”的普通化学实验课程，阐明阴离子（如硝酸盐）与食物蛋白质的相互作用的生化意义。硝酸盐是生命必需的无机离子。在细菌和植物中，硝酸盐是一种被充分研究的营养物质和信号离子；在人类中，硝酸盐被活性氮氧化物所掩盖。为了剖析硝酸盐在人类生物学中的贡献，需要对其细胞摄取、调节和目标有一个基本的了解。具有硝酸盐选择性荧光生物传感器的光学成像方法可以加速在活细胞中获得这些见解的路径。然而，由于水阴离子识别的固有困难，这种技术仍然很少见。为了克服这一根本性的挑战，Dodani研究小组将研究蛋白质作为硝酸盐的生物超分子宿主。具体来说，硝酸盐结合蛋白正在通过生物信息学进行鉴定，并将用生物物理方法进行表征，并用于设计用于细胞应用的基于荧光蛋白的传感器。这种跨学科的方法有望开始解开序列水平的分子决定因素，赋予和调整生物分子硝酸盐识别。目标是开发和/或鉴定硝酸盐的选择性蛋白质传感器，这是化学/生物学界面的主要挑战。这门科学的更大的分子主题是阐明硝酸盐在生物学中的作用。在这个项目中开发的基于蛋白质的工具有望帮助解决这个基本问题，并在化学-生物学界面上产生广泛的科学影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Chemistry of Life Processes Program in the Chemistry Division, Sheel C. Dodani from The University of Texas at Dallas will study the biochemistry of the nitrate oxyanion. It is widely recognized that nitrate is required for essential functions in bacteria and plants such as respiration, growth, and signaling. However, much remains unknown about the beneficial and detrimental effects of nitrate in humans. To fill this knowledge gap, the Dodani Lab will study and engineer protein sensors in an effort to develop nitrate-selective sensors. If successful, such proteins have the potential to detect nitrate in living cells, and, in the longer term, shed light on the biochemical roles of nitrate. These efforts will be coupled to an educational plan that seeks to illustrate the biochemical significance of anions such as nitrate through interactions with food-based proteins by developing a general chemistry laboratory course for undergraduate students entitled Hofmeister in the Kitchen.Nitrate is an essential inorganic ion for life. In bacteria and plants, nitrate is a well-studied nutrient and signaling ion; in humans, nitrate has been overshadowed by reactive nitrogen oxides. To dissect the contributions of nitrate in human biology, a fundamental understanding of its cellular uptake, regulation, and targets is needed. Optical imaging approaches with nitrate-selective fluorescent biosensors can accelerate the path to gain these insights in living cells. However, such technologies remain rare due to the inherent difficulty of aqueous anion recognition. To overcome this fundamental challenge, the Dodani research team will investigate proteins as biological supramolecular hosts for nitrate. Specifically, nitrate binding proteins are being identified through bioinformatics, and will be characterized with biophysical methods, and used to engineer fluorescent protein-based sensors for cellular applications. This interdisciplinary approach is expected to begin to unravel the sequence level molecular determinants that confer and tune biomolecular nitrate recognition. The goal is to develop and/or identify selective protein sensors for nitrate, a major challenge at the chemistry/biology interface. The larger molecular theme of this science is to illuminate the roles of nitrate in biology. The protein-based tools being developed in this project are expected to help address this basic question and as such have broad scientific impact at the chemistry-biology interface.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.