US-Bulgaria Cooperative Research on Oxidative Effects of the Superoxide Radical in Escherichia Coli

这个由欧文·弗里多维奇博士和斯蒂芬·利奥切夫博士合作的美国-保加利亚项目是关于“超氧阴离子自由基在大肠杆菌中的氧化作用”。研究人员对超氧阴离子自由基的毒性效应提出了一种新的解释，以解释文献中已有的许多观察结果，这些观察结果有助于进行实验探索。目前的正统观点认为，超氧化物是过氧化氢的前体，也是铁离子的还原剂。相反，研究人员认为O2、O2和H2O2是直接氧化剂，并认为各种连接形式的Fe(II)是这些氧化剂的重要靶标。他们发现，许多含有ı4Fe-4S！的脱水酶会被氧气迅速氧化失活。这一结果将有助于阐明氧毒性的机制，以及紫精、苯二酚、芳基硝基化合物和其他氧化还原活性化合物的氧依赖毒性。这个生物化学科学项目通过使保加利亚和美国的顶尖专家能够将互补的人才结合在一起，并在相互感兴趣和能力很强的领域汇集资源，从而实现了促进科学知识的计划目标。

This US-Bulgaria project between Dr. Irwin Fridovich and Dr. Stephan Liochev is on "Oxidation Effects of the Superoxide Radical in Escherichia Coli." The researchers propose a novel explanation for the toxic effects of the superoxide radical, to account for many observations already in the literature which lend themselves to experimental probing. Current orthodoxy views superoxide as a precursor of hydrogen peroxide and as a reductant for ferric ion. The researchers, in contrast, view O2, O2 and H2O2 as direct oxidants and consider Fe(II), in its various ligated forms, to be an important target for these oxidants. They have found that a number of ı4Fe-4S!-containing dehydrases are rapidly oxidatively inactivated by O2. The results should shed light on the mechanisms of oxygen toxicity and of the oxygen-dependent toxicities of viologens, quinones, aryl nitro compounds and of other redox-active compounds. This project in biochemistry science fulfills the program objective of advancing scientific knowledge by enabling leading experts in Bulgaria and the United States to combine complementary talents and pool resources in areas of strong mutual interest and competence.