Superoxide dismutase activity enabled by a redox-active ligand rather than metal

Catalytic activity tunable ceria nanoparticles prevent chemotherapy-induced acute kidney injury without interference with chemotherapeutics

“…CNPs demonstrated superoxide dismutase (SOD)-like activity under neutral and acidic conditions ( Supplementary Fig. 4), which can catalyze the dismutation of superoxide radicals (•O 2 − ) into H 2 O 2 31 . Intriguingly, CNPs are highly active for decomposing H 2 O 2 in a neutral environment but inert under acidic conditions, as evaluated by oxygen production (Fig.…”

Direct Zinc Finger Protein Persulfidation by H2S Is Facilitated by Zn2+

“…, or iii) shifting the redox potential of O 2 to a more positive value favoring superoxide formation . The first role is of particular interest (see Scheme S1 for a potential mechanism), as there is precedence for the metal facilitating reactivity both in proteins—iron and manganese dioxygenases—and in protein model complexes—zinc superoxide dismutate models with a quinoline ligand . In both instances, the metal is required to bring the reactive molecules into close proximity to each other, but does not change its oxidation state (for Fe and Mn) .…”

“…The reactivity of Zn 2 -TTP-2D with H 2 Sw as assessed by the lowtemperature high-resolution mass spectrometric technique, "cryo" electrospray time-of-flight mass spectrometry (ESI-TOF-MS) (+ 4 8 8C). Thec onditions of cryo-ESI-TOF-MS are gentle enough for metal coordination to be retained, [7] as illustrated by recent studies in which reactive sulfur species were observed to be transiently coordinated to the iron center of heme proteins. [2,8] Thecryo-ESI-MS spectrum of Zn 2 -TTP-2D (50 mm,2 0mm (NH 4 ) 2 CO 3 ,p H7.3) was recorded and ap eak corresponding to Zn 2 -TTP-2D identified (see Fig-ure S1 in the Supporting Information).…”

Direct Zinc Finger Protein Persulfidation by H2S Is Facilitated by Zn2+

“…[16] Thefirst role is of particular interest (see Scheme S1 for apotential mechanism), as there is precedence for the metal facilitating reactivity both in proteins-iron and manganese dioxygenases [17] -and in protein model complexes-zinc superoxide dismutate models with aq uinoline ligand. [7] In both instances,t he metal is required to bring the reactive molecules into close proximity Angewandte Chemie Zuschriften to each other,but does not change its oxidation state (for Fe and Mn). [7,17] Furthermore,t he binding of superoxide to zinc has been suggested to be essential for copper-catalyzed superoxide dismutation in CuZnSOD.…”

“…[7] In both instances,t he metal is required to bring the reactive molecules into close proximity Angewandte Chemie Zuschriften to each other,but does not change its oxidation state (for Fe and Mn). [7,17] Furthermore,t he binding of superoxide to zinc has been suggested to be essential for copper-catalyzed superoxide dismutation in CuZnSOD. [18] Future spectroscopic studies will allow us to further identify intermediates and define amechanism.…”