title: Classical Cys2His2 zinc finger peptides are rapidly oxidized by either H2O2 or O2 irrespective of metal coordination.
abstract: ZIF268, a member of the classical zinc finger protein family, contains three Cys(2)His(2) zinc binding domains that together recognize the DNA sequence 5'-AGCGTGGGCGT-3'. These domains can be fused to an endonuclease to make a chimeric protein to target and cleave specific DNA sequences. A peptide corresponding to these domains, named ZIF268-3D, has been prepared to determine if the zinc finger domain itself can promote DNA cleavage when a redox active metal ion, Fe(II), is coordinated. The UV-vis absorption spectrum of Fe(II)-ZIF268-3D is indicative of Fe(II) coordination. Using fluorescence anisotropy, we demonstrate that Fe(II)-ZIF268-3D binds selectively to its target DNA in the same manner as Zn(II)-ZIF268-3D. In the presence of added oxidant, H(2)O(2) or O(2), DNA cleavage is not observed by Fe(II)-ZIF268-3D. Instead, the peptide itself is rapidly oxidized. Similarly, Zn(II)-ZIF268-3D and apo-ZIF268-3D are rapidly oxidized by H(2)O(2) or O(2), and we propose that ZIF268-3D is highly susceptible to oxidation.
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201-1180, USA.
authors.forename: Seung Jae
authors.initials: SJ
authors.lastname: Lee
authors.forename: Jamie L
authors.initials: JL
authors.lastname: Michalek
authors.forename: Angelique N
authors.initials: AN
authors.lastname: Besold
authors.forename: Steven E
authors.initials: SE
authors.lastname: Rokita
authors.forename: Sarah L J
authors.initials: SL
authors.lastname: Michel
mesh_terms: D003545:Cysteine / Q000737:chemistry*; D004247:DNA / Q000737:chemistry; D006639:Histidine / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D016335:Zinc Fingers
chemical_list: D010455:Peptides; D006639:Histidine; D004247:DNA; D006861:Hydrogen Peroxide; D003545:Cysteine; D010100:Oxygen