Copper has many roles in biology that involve the change of coordination sphere and/or oxidation state of the copper ion. Consequently, the study of copper in heterogeneous environments is an important area in biophysics. EPR is a primary technique for the investigation of paramagnetic copper, which is usually the isolated Cu(II) ion, but sometimes as Cu(II) in different oxidation states of mul...

The anthracis repressor (AntR) is a manganese-activated transcriptional regulator from Bacillus anthracis and is a member of the diphtheria toxin repressor (DtxR) family of proteins. In this paper, we characterize the Mn(II) binding and protein dimerization state using a combination of continuous wave (cw) and pulsed EPR methods. Equilibrium metal binding experiments showed that AntR binds 2 eq...

Paramagnetic complexes of iron (III), manganese (II), and cobalt (II) protoporphyrins IX and apohemoproteins react with nitric oxide to form spectroscopically distinct compounds. Optical and electron paramagnetic resonance (EPR) studies suggest that a l-electron transfer between nitric oxides and metal ions which occurs in these reactions results in the formation of spin-paired complexes of the...

This minireview describes the practical use of assay systems to detect nitric oxide (NO) by electron paramagnetic resonance (EPR) spectroscopy for evaluation of endothelial functions. The iron(II)-dithiocarbamate complexes, such as iron(II)-(N-methyl-D-glucamine dithiocarbamate), are commonly used in EPR detection of NO both in vivo and in vitro. However, due to their redox activity, these comp...

Paramagnetic complexes of iron (III), manganese (II), and cobalt (II) protoporphyrins IX and apohemoproteins react with nitric oxide to form spectroscopically distinct compounds. Optical and electron paramagnetic resonance (EPR) studies suggest that a l-electron transfer between nitric oxides and metal ions which occurs in these reactions results in the formation of spin-paired complexes of the...

Nitric oxide (NO) production in the rat placenta was monitored and quantified by electron paramagnetic resonance (EPR) spectroscopy with hemoglobin and an Fe-N-(dithiocarboxy)sarcosine (DTCS) complex as NO-trapping reagents. Expression of nitric oxide synthase (NOS) isoforms was also examined by quantitative RT-PCR analysis. The EPR spectrum of the placenta with hemoglobin trapping showed a thr...

Paramagnetic complexes of iron (III), manganese (II), and cobalt (II) protoporphyrins IX and apohemoproteins react with nitric oxide to form spectroscopically distinct compounds. Optical and electron paramagnetic resonance (EPR) studies suggest that a l-electron transfer between nitric oxides and metal ions which occurs in these reactions results in the formation of spin-paired complexes of the...