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

化学学部的生命过程化学项目资助了这项工作。来自加州州立理工大学圣路易斯奥比斯波分校（calpoly）的Emily Fogle和Eric Jones教授研究了含硫硫酯化合物的酶催化反应。硫酯是一类活性分子，在化学和生物化学中都具有重要的作用。硫酯是许多生物合成反应中的常见中间体，包括类固醇生产的起始原料。该研究考察了硫酯与含氮分子的酶促反应，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）。本研究被纳入一个自我维持的研究经验，发生在一个高年级本科实验班。这项工作被纳入生物化学专业大三学生必修的高级生物化学课程。我们的目标是让所有加州理工学院的生物化学专业学生都有一个真实的研究经历，并获得知识、技能和自信。该研究项目研究了硫酯与氮亲核试剂的酶促反应（氨解反应），并表征了n -乙酰谷氨酸合成酶（NAGS）的一种常见细菌形式。硫酯是一类非常重要的反应性羧酸衍生物，其中硫原子取代了离去基位置上典型的氧或氮原子。硫酯通常比同等的氧酯对亲核试剂反应更强，这一因素在有机化学和生物化学中都起着重要的作用。这项工作的具体科学目的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。这项工作也被纳入一个自我维持的研究经验，发生在一个高级实验室班。

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.