Efficient Oxidation and Destabilization of Zn(Cys)4 Zinc Fingers by Singlet Oxygen1. (7th July 2014)

• Record Type: Journal Article
• Authors: Lebrun, Vincent; Tron, Arnaud; Scarpantonio, Luca; Lebrun, Colette; Ravanat, Jean‐Luc; Latour, Jean‐Marc; McClenaghan, Nathan D.; Sénèque, Olivier
• Is Part Of: Angewandte Chemie. Volume 126:Number 35(2014)
• Page Start: 9519
• Page End: 9522
• Publication Date: 2014-07-07
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201405333
• Languages: English
• ISSNs: 0044-8249

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Singlet oxygen (¹O₂) plays an important role in oxidative stress in all types of organisms, most of them being able to mount a defense against this oxidant. Recently, zinc finger proteins have been proposed to be involved in its cellular detection but the molecular basis of this process still remains unknown. We have studied the reactivity of a Zn(Cys)₄ zinc finger with ¹O₂ by combinations of spectroscopic and analytical techniques, focusing on the products formed and the kinetics of the reaction. We report that the cysteines of this zinc finger are oxidized to sulfinates by ¹O₂. The reaction of the ZnS₄ core with ¹O₂ is very fast and efficient with almost no physical quenching of ¹O₂. A drastic (ca. five orders of magnitude) decrease of the Zn²⁺ binding constant was observed upon oxidation. This suggests that the Zn(Cys)₄ zinc finger proteins would release their Zn²⁺ ion and unfold upon reaction with ¹O₂ under cellular conditions and that zinc finger sites are likely targets for ¹O₂.</p> </abstract>