RUI: Mechanistic study of short N-acetylglutamate synthetases and incorporation into a course-based undergraduate research experience

化学部的生命过程化学计划为这项工作提供资金。加州理工州立大学圣路易斯奥比斯波(Cal Poly)的艾米丽·福格尔和埃里克·琼斯教授研究了含硫化合物硫代酯的酶催化反应。硫代酯是一类在化学和生物化学中都具有重要作用的活性分子。硫代酯是许多生物合成反应中常见的中间体，包括生产类固醇的起始原料。这项研究检查了硫代酯与含氮分子的酶反应，并研究了一种常见的细菌形式的酶NAGS(N-乙酰谷氨酸合成酶)。这项研究被纳入了一项自给自足的研究体验，该体验发生在高年级本科生实验室课堂上。这项工作被纳入生物化学专业三年级必修的高级生物化学课程。我们的目标是让加州大学保利分校所有生物化学专业的学生都有真实的研究经验，并获得知识、技能和自信。该研究项目研究了硫代酯与氮亲核试剂的酶反应(氨解反应)，并表征了一种常见的细菌形式的N-乙酰谷氨酸合成酶(NAGS)。硫代酯是一类非常重要的活性羧酸衍生物，其中硫原子取代了典型的离开基团位置的氧或氮原子。硫代酯通常比同等的氧代酯对亲核试剂具有更高的活性，这一因素在有机化学和生物化学中都发挥了重要作用。这项工作的具体科学目标是纯化和动力学表征三种细菌NAGS酶，并确定NAGS催化反应的氮和硫动力学同位素效应。这项工作也被纳入了一项自给自足的研究体验，这项研究发生在上级实验室课堂上。

The Chemistry of Life Processes Program in the Chemistry Division funds this work. Professors Emily Fogle and Eric Jones from California Polytechnic State University, San Luis Obispo (Cal Poly) study enzyme catalyzed reactions of compounds containing sulfur, thioesters. Thioesters are a class of reactive molecules with important roles in both chemistry and biochemistry. Thioesters are common intermediates in many biosynthetic reactions, including starting materials for steroid production. The research examines enzymatic reactions of thioesters with nitrogen-containing molecules and to studies of a common bacterial form of the enzyme NAGS (N-acetylglutamate synthase). This research is incorporated into a self-sustaining research experience that occurs in an upper division undergraduate laboratory class. The work is incorporated into a required, advanced biochemistry course that biochemistry majors take in their junior year. The goal is for all biochemistry majors at Cal Poly to have an authentic research experience and gain knowledge, skills and self-confidence. The research project studies the enzymatic reaction of thioesters with nitrogen nucleophiles (aminolysis reactions) and characterizes a common bacterial form of N-acetylglutamate synthase (NAGS). Thioesters are a very important class of reactive carboxylic acid derivatives in which a sulfur atom replaces the typical oxygen or nitrogen atom in the leaving group position. Thioesters are generally more highly reactive toward nucleophiles than the equivalent oxoesters and this factor has resulted in important roles in both organic chemistry and biochemistry. The specific scientific aims of this work are to purify and kinetically characterize three bacterial NAGS enzymes and to determine the nitrogen and sulfur kinetic isotope effects for the NAGS-catalyzed reaction. This work is also incorporated into a self-sustaining research experience that occurs in an upper division laboratory class.