Nitrosylation of Nitric‐Oxide‐Sensing Regulatory Proteins Containing [4Fe‐4S] Clusters Gives Rise to Multiple Iron–Nitrosyl Complexes. (25th October 2016)

• Record Type: Journal Article
• Authors: Serrano, Pauline N.; Wang, Hongxin; Crack, Jason C.; Prior, Christopher; Hutchings, Matthew I.; Thomson, Andrew J.; Kamali, Saeed; Yoda, Yoshitaka; Zhao, Jiyong; Hu, Michael Y.; Alp, Ercan E.; Oganesyan, Vasily S.; Le Brun, Nick E.; Cramer, Stephen P.
• Is Part Of: Angewandte Chemie. Volume 128:Number 47(2016)
• Page Start: 14795
• Page End: 14799
• Publication Date: 2016-10-25
• Subjects: Eisen-Schwefel-Cluster -- Genregulation -- Kernresonanzschwingungsspektroskopie -- Stickstoffmonoxid -- Synchrotronstrahlung; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201607033
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: The reaction of protein‐bound iron–sulfur (Fe‐S) clusters with nitric oxide (NO) plays key roles in NO‐mediated toxicity and signaling. Elucidation of the mechanism of the reaction of NO with DNA regulatory proteins that contain Fe‐S clusters has been hampered by a lack of information about the nature of the iron‐nitrosyl products formed. Herein, we report nuclear resonance vibrational spectroscopy (NRVS) and density functional theory (DFT) calculations that identify NO reaction products in WhiD and NsrR, regulatory proteins that use a [4Fe‐4S] cluster to sense NO. This work reveals that nitrosylation yields multiple products structurally related to Roussin's Red Ester (RRE, [Fe2 (NO)4 (Cys)2 ]) and Roussin's Black Salt (RBS, [Fe4 (NO)7 S3 ]. In the latter case, the absence of 32 S/ 34 S shifts in the Fe−S region of the NRVS spectra suggest that a new species, Roussin's Black Ester (RBE), may be formed, in which one or more of the sulfide ligands is replaced by Cys thiolates.