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

California Polytechnic State University Foundation, San Luis Obispo CA

Investigators

Abstract

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.