Peter Doan

Internal dynamics of a supramolecular nanofibre

Nature Materials · 2014-05-23 · 167 citations

Oxygen and the copper chaperone CCS regulate posttranslational activation of Cu,Zn superoxide dismutase

Proceedings of the National Academy of Sciences · 2004-04-02 · 146 citations

Oxidative stress leads to the up-regulation of many antioxidant enzymes including Cu,Zn superoxide dismutase (SOD1) via transcriptional mechanisms; however, few examples of posttranslational regulation are known. The copper chaperone for SOD1 (CCS) is involved in physiological SOD1 activation, and its primary function is thought to be delivery of copper to the enzyme. Data presented here are consistent with a previously uncharacterized function for CCS in the SOD1 pathway, namely mediating enzym…

An Organometallic Intermediate during Alkyne Reduction by Nitrogenase

Journal of the American Chemical Society · 2004-07-20 · 120 citations

Nitrogenase is the metalloenzyme that catalyzes the nucleotide-dependent reduction of N(2), as well as reduction of a variety of other triply bonded substrates, including the alkyne, acetylene. Substitution of the alpha-70(Val) residue in the nitrogenase MoFe protein by alanine expands the range of substrates to include short-chain alkynes not reduced by the unaltered protein. Rapid freezing of the alpha-70(Ala) nitrogenase MoFe protein during reduction of the alkyne propargyl alcohol (HC triple…

⁵⁷Fe ENDOR Spectroscopy and ‘Electron Inventory’ Analysis of the Nitrogenase E₄Intermediate Suggest the Metal-Ion Core of FeMo-Cofactor Cycles Through Only One Redox Couple

Journal of the American Chemical Society · 2011-10-07 · 78 citations

N(2) binds to the active-site metal cluster in the nitrogenase MoFe protein, the FeMo-cofactor ([7Fe-9S-Mo-homocitrate-X]; FeMo-co) only after the MoFe protein has accumulated three or four electrons/protons (E(3) or E(4) states), with the E(4) state being optimally activated. Here we study the FeMo-co (57)Fe atoms of E(4) trapped with the α-70(Val→Ile) MoFe protein variant through use of advanced ENDOR methods: 'random-hop' Davies pulsed 35 GHz ENDOR; difference triple resonance; the recently d…

Coordination of the Copper Centers in Particulate Methane Monooxygenase: Comparison between Methanotrophs and Characterization of the Cu_CSite by EPR and ENDOR Spectroscopies

Journal of the American Chemical Society · 2021 · 45 citations

is the likely site of biological methane oxidation by pMMO, a conclusion that will serve as a foundation for proposals regarding the mechanism of this reaction.