Previously, we reported that Arg177 is involved in MnII binding at the MnII binding site of manganese peroxidase isozyme 1 (MnP1) of Phanerochaete chrysosporium by examining two mutants: R177A and R177K. We now report on additional mutants: R177D, R177E, R177N, and R177Q. These new mutant enzymes were produced by homologous expression in P. chrysosporium and were purified to homogeneity. The mo...

Electron paramagnetic resonance (EPR) spectroscopy is used to study the binding of MnII ions to a tertiary stabilized hammer-head ribozyme (tsHHRz) and to compare it with the binding to the minimal hammerhead ribozyme (mHHRz). Continuous wave EPR measurements show that the tsHHRz possesses a single high-affinity MnII binding site with a KD of < or =10 nM at an NaCl concentration of 0.1 M. This ...

Inhibition of manganese peroxidase by cadmium was studied under steady-state and transient-state kinetic conditions. CdII is a reversible competitive inhibitor of MnII in the steady state with Ki approximately 10 microM. CdII also inhibits enzyme-generated MnIII-chelate-mediated oxidation of 2,6-dimethoxyphenol with Ki approximately 4 microM. CdII does not inhibit direct oxidation of phenols su...

Two carboxylate-bridged one-dimensional chain complexes, {[MnII(MeOH)2][FeIII(L)2]2}n (1) and {[MnII(DMF)2][MnIII(L)2]2·DMF}n (2) [H2L = ((2-carboxyphenyl)azo)-benzaldoxime], containing a low-spin [FeIII(L)2]− or [MnIII(L)2]− unit were synthesized. Magnetic measurements show that the adjacent high-spin MnII MIII ions display weak antiferromagnetic coupling via syn–anti carboxyl bridges, with J ...

We report the synthesis, magnetic EPR and conducting properties of a new manganese complex [MnII(hfac)2(IMHPhOPh)]2[MnII(hfac)3](IMH2PhOPh) (1), containing reduced forms (IMHPhOPh IMH2PhOPh) NIT-PhOPh radical (NIT-PhOPh = 2,4‘-benzoxo-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide). Magnetic susceptibility studies reveal presence weak antiferromagnetic exchange interactions between metal ions, w...

Two novel heteropolyoxomolybdate [XMo₈O31]n- (X = Ge(1) or P(2)) manganese carbonyl derivatives [(CH₃)₄N]₆H₆{MnII(GeMo₈O31)[MnI(CO)₃]₂}₂·12H₂O (1) and [(CH₃)₄N]₄H₆{MnII(PMo₈O31)[MnI(CO)₃]₂}₂·14H₂O (2), have been successfully synthesized and characterized in the solid state by single crystal X-ray diffraction, IR and thermogravimetric analysis, and in solution by UV-Vis spectroscopy and electroc...

This paper investigates the comproportionation reaction of MnII with [Formula: see text] as a route for manganese oxide nanoparticle synthesis in the protein ferritin. We report that [Formula: see text] serves as the electron acceptor and reacts with MnII in the presence of apoferritin to form manganese oxide cores inside the protein shell. Manganese loading into ferritin was studied under acid...

Manganese(II) complex [(Bn-tpen)MnII]2+ activated dioxygen for oxidation of cyclohexene in acetonitrile (MeCN) and methanol (MeOH). In MeCN, ketone (2-cyclohexen-1-one), alcohol (2-cyclohexen-1-ol) and small amounts of epoxide (cyclohexene oxide) were produced in this reaction, while in MeOH only ketone was formed. In the most efficient experiment, the combination of 2.5 × 10-4 mol% [(Bn-tpen)M...

first row transition metal complexes of phthalocyanine are employed as catalysts for the oxidation of cyclohexene and cyclooctene using iodosylbenzene and pentafluoroiodosyl benzene. the catalysis was performed in dichloromethane: methanol:water (80:18:2) solvent mixture.  the products of the catalysis for cyclohexene are epoxycyclohexane, 2-cyclohexene-1-ol and 2-cyclohexene-1-one whereas for ...

The title compound, [Mn2(C7H4NO4)4(C6H7N)4] or [Mn2(μ-NBz)2(κ2-NBz)2(4-Mepy)4], where NBz is 4-nitro-benzoate and 4-Mepy is 4-methyl-pyridine, is a centrosymmetric dinuclear complex in which the MnII atoms are bridged by two NBz ligands with Mn⋯Mn = 4.1324 (4) Å. The MnII atom in this dimeric species is present in a distorted octa-hedral environment with the four coordinating O atoms forming th...