Victoria G Snider1, Erik R Farquhar2, Mark Allen1, Ayah Abu-Spetani1, Anusree Mukherjee3. 1. Department of Chemistry, University of Alabama in Huntsville, 301 Sparkman Dr NW, Huntsville, AL 35899, United States. 2. Case Western Reserve University Center for Synchrotron Biosciences, National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY 11973, United States. 3. Department of Chemistry, University of Alabama in Huntsville, 301 Sparkman Dr NW, Huntsville, AL 35899, United States. Electronic address: am0095@uah.edu.
Abstract
Superoxide plays a key role in cell signaling, but can be cytotoxic within cells unless well regulated by enzymes known as superoxide dismutases (SOD). Nickel superoxide dismutase (NiSOD) catalyzes the disproportion of the harmful superoxide radical into hydrogen peroxide and dioxygen. NiSOD has a unique active site structure that plays an important role in tuning the potential of the nickel center to function as an effective catalyst for superoxide dismutation with diffusion controlled rates. The synthesis of structural and functional analogues of NiSOD provides a route to better understand the role of the nickel active site in superoxide dismutation. In this work, the synthesis of a series of nickel complexes supported by nitrogen rich pentadentate ligands is reported. The complexes have been characterized through absorption spectroscopy, mass spectrometry, and elemental analysis. X-ray absorption spectroscopy was employed to establish the oxidation state and the coordination geometry around the metal center. The reactivity of these complexes toward KO2 was evaluated to elucidate the role of the coordination sphere in controlling superoxide dismutation reactivity.
Superoxide plays a key role in cell n class="Chemical">signaling, but can be cytotoxic within cells unless well regulated by enzymes known as superoxide dismutases (SOD). Nickelsuperoxide dismutase (NiSOD) catalyzes the disproportion of the harmful superoxide radical into hydrogen peroxide and dioxygen. NiSOD has a unique active site structure that plays an important role in tuning the potential of the nickel center to function as an effective catalyst for superoxide dismutation with diffusion controlled rates. The synthesis of structural and functional analogues of NiSOD provides a route to better understand the role of the nickel active site in superoxide dismutation. In this work, the synthesis of a series of nickel complexes supported by nitrogen rich pentadentate ligands is reported. The complexes have been characterized through absorption spectroscopy, mass spectrometry, and elemental analysis. X-ray absorption spectroscopy was employed to establish the oxidation state and the coordination geometry around the metal center. The reactivity of these complexes toward KO2 was evaluated to elucidate the role of the coordination sphere in controlling superoxide dismutation reactivity.
Authors: Ellen P Broering; Stephanie Dillon; Eric M Gale; Ramsey A Steiner; Joshua Telser; Thomas C Brunold; Todd C Harrop Journal: Inorg Chem Date: 2015-04-02 Impact factor: 5.165
Authors: S B Choudhury; J W Lee; G Davidson; Y I Yim; K Bose; M L Sharma; S O Kang; D E Cabelli; M J Maroney Journal: Biochemistry Date: 1999-03-23 Impact factor: 3.162