Excellence in Research: Development of a Fluorescent Assay to Measure LAT1 Transport

在化学系生命过程化学项目和历史上黑人高等院校卓越研究项目（HBCU-EiR）的支持下，杰奎琳·史密斯博士将研究小分子通过天然转运体的运输。细胞的存活依赖于氨基酸、碳水化合物和其他有价值的生化物质等营养物质进入细胞。营养物质的输送是由转运蛋白实现的，转运蛋白是位于细胞膜上的蛋白质。对这些蛋白质的研究具有挑战性。史密斯博士的研究旨在创造新的化学探针来研究转运蛋白，特别是大氨基酸转运蛋白（LAT1）。该研究还将侧重于开发一种快速识别作为LAT1底物的小分子的方法。这个项目将为鲍伊州立大学的学生提供一个探索蛋白质生物化学和其他现代化学生物学技术的机会。大氨基酸转运蛋白（large amino acid transporter, LAT1）是一种关键的营养转运蛋白，在脑和胎盘细胞以及一般高能量需求细胞中高度表达。作为一种跨膜蛋白，LAT1的结构直到最近才被确定，并且LAT1的运输传统上使用放射性同位素测定。虽然计算方法已用于研究LAT1，但缺乏验证计算预测的实验方法。史密斯博士将继续研究含有LAT1的蛋白脂质体。利用表面等离子体共振（SPR）研究蛋白脂质体内与LAT1结合的小分子。新开发的荧光底物将用于筛选可通过LAT1运输的分子。本研究开发的工具将用于更好地了解LAT1与小分子的结合和运输。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 and the Historically Black Colleges and Universities Excellence in Research (HBCU-EiR) Program, Dr. Jacqueline Smith will investigate the transport of small molecules through native transporters. Cell survival depends on the delivery of nutrients such as amino acids, carbohydrates and other valuable biochemicals into the cell. The delivery of the nutrients is enabled by transporters, which are proteins located in the cell membrane. The study of these proteins is challenging. Dr. Smith’s research seeks to create novel chemical probes to study a transporter, specifically the large amino acid transporter (LAT1). The research will also focus on the development of a method for rapid identification of small molecules that are substrates for LAT1. This project will give students at Bowie State an opportunity to explore protein biochemistry and other modern chemical biology techniques. The large amino acid transporter (LAT1) is a key nutrient transporter that is highly expressed in the cells in the brain and placenta and in cells with high energy demand in general. As a transmembrane protein, the structure of LAT1 has been determined only recently and transport by LAT1 was traditionally measured using radioisotope assays. Although computational methods have been used to study LAT1, experimental methods for validation of the computational predictions are lacking. Dr. Smith will pursue the development of proteoliposomes that contain LAT1. The small molecule binding to LAT1 within the proteoliposomes will be studied by surface plasmon resonance (SPR). Newly developed fluorescent substrates will be used to screen for molecules that can be transported through LAT1. The tools developed in this study will be applied to gain a better understanding of the binding to and transport of small molecules by LAT1.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.