U.S.-Italy Cooperative Research: Structure and Function of Glutamate Synthase

该奖项将支持埃默里大学的Dale Edmondson教授与米兰大学的Bruno Curti博士及其团队开展合作活动。研究人员将重点研究谷氨酸合成酶，它在固氮微生物的氮同化中起着关键作用。具体来说，他们将继续研究黄素和铁硫中心在两种固氮细菌——巴西偶氮螺旋菌和vinelandii偶氮杆菌中分离的谷氨酸合成酶的催化机制中的作用。其中第一种是与植物根系有关的嗜微气细菌，而第二种是一种有氧自由生活的土壤细菌。酶的实验工作将在埃默里大学和米兰大学进行。氮螺旋藻谷氨酸合成酶将在米兰纯化和鉴定，而固氮菌酶将在亚特兰大纯化。美国实验室将提供酶系统物理测量方面的专业知识。Edmondson博士在生物物理化学领域有着广泛的背景，尤其是黄素蛋白，而Curti博士的团队在谷氨酸合成酶方面已经研究了几年，他们之间的互动应该是互惠互利的。此外，它有可能在谷氨酸合酶的基本结构和机制以及氮代谢的新信息方面取得实质性成果。

This award will support Prof. Dale Edmondson of Emory University to engage in collaborative activities with Dr. Bruno Curti and his group at the University of Milan. The researchers will focus on the enzyme glutamate synthase, which plays a key role in the assimilation of nitrogen in nitrogen-fixing microorganisms. Specifically, they will pursue the investigation of the roles of the flavin and iron-sulfur centers in the catalytic mechanisms of glutamate synthase isolated from two nitrogen-fixing bacteria, Azospirillum brasilense and Azotobacter vinelandii, the first of which is microaerophilic and associated with plant roots while the second is an aerobic free-living soil bacterium. Experimental work on the enzymes will be conducted at both Emory and Milan. Azospirillum glutamate synthase will be purified and characterized in Milan while the Azotobacter enzyme will be purified in Atlanta. The U.S. lab will provide the expertise in physical measurements on the enzyme systems. The interaction between Dr. Edmondson, who has an extensive background in areas of biophysical chemistry in general and flavoproteins in particular, and Dr. Curti's group, which has worked with the enzyme glutamate synthase for several years, should be of mutual benefit. Furthermore, it has the potential for yielding substantial results concerning the basic structure and mechanism of glutamate synthase as well as new information concerning nitrogen metabolism.