The demethylation of histone H3 lysine 27 is catalyzed by the FeII/2-oxoglutarate-dependent demethylase from Class 6 (KDM6). KDM6 family (KDM6A/KDM6B) catalyzes trimethylated H3K27, which involves iron-oxo intermediates, including superoxo (FeIII−OO⋅−), Ferryl (FeIV=O), and hydroxo (FeIII−OH) complexes. study determines role second coordination sphere long-range interacting residues in KDM6′s c...

We have synthesized and characterized a new class of heme-peptide complexes using disulfide-linked hairpin-turn and cyclic peptides and compared these to their linear analogues. The binding affinities, helicities, and mechanism of binding of linear, hairpin, and cyclic peptides to [FeIII(coproporphyrin-I)]+ have been determined. In a minimalist approach, we utilize amphiphilic peptide sequences...

Through the strategic design of ligands based on amino acids, structural diversity in chiral coordination architectures of CuII is demonstrated with six new examples: {[Cu(L-HTyrbenz)2]·CH3OH·H2O}n (1), {[Cu(L-HSerbenz)2]·3H2O}n (2), {[Cu(L-HTyrthio)2]·H2O}n (3), [Cu(L-HTyr4-pyr)2(H2O)]·2H2O (4), [Cu(L-HSerthio)2(H2O)] (5), and [Cu(L-Phethio)2(H2O)]·3H2O (6) [where L-H2Tyrbenz = L-N-(benzyl)-ty...

The copper–phenanthroline complex CuI(Phen)2 was the first artificial nuclease studied in biology. mechanism responsible for this activity involves CuII(Phen)2 and H2O2. Even if H2O2/Cu systems have been extensively biology oxidative chemistry, most of these studies were carried out at physiological pH only, little information is available on generation radicals by H2O2/CuII-Phen system. In con...

A method was developed for the separation of CdII, PbII, PtII, CoII, NiII, BiIII, CrII, CuII and HgII bis(2-hydroxyethyl)dithiocarbamate (HEDTC) complexes by micellar electrokinetic capillary chromatography. The complexes were formed by pre-capillary reaction of the metal ions with an excess of the ligand and then separated using a 100 mm borate buffer (pH 9.2) containing 4% methanol (v/v), 10 ...

Few families of compounds have been as intensely studied as iron porphyrin complexes. In spite of this, a truly four-coordinate Fe(III) porphyrin cation has never before been reported.1 The exceptional electrophilicity of the four-coordinate [FeIII(Porph)]+ cation will even coordinate arene solvent upon crystallization if the counteranion is extremely non-coordinating, as in the work of Reed wi...

Redox-inactive metal ions that function as Lewis acids play pivotal roles in modulating reactivities of oxygen-containing metal complexes in a variety of biological and biomimetic reactions, including dioxygen activation/formation and functionalization of organic substrates. Mononuclear nonheme iron(III)-peroxo species are invoked as active oxygen intermediates in the catalytic cycles of dioxyg...

We report direct electrochemistry of the iNOS heme domain in a DDAB film on the surface of a basal plane graphite electrode. Cyclic voltammetry reveals FeIII/II and FeII/I couples at -191 and -1049 mV (vs Ag/AgCl). Imidazole and carbon monoxide in solution shift the FeIII/II potential by +20 and +62 mV, while the addition of dioxygen results in large catalytic waves at the onset of FeIII reduct...