Aldehyde oxidase from rabbit liver was studied by electron paramagnetic resonance (EPR) spectroscopy. Reduction by substrate elicited three types of signals characteristic of free radicals, molybdenum(V), and a non-heme iron complex, respectively. The properties of these signals are described, and the representation of each species in the corresponding signal is quantitatively assessed. Under t...

Objectives/Goals The goals of this project were to determine a) whether Copper-induced oxidation of Bilirubin leads to the bluish black pigment noted in Pigmented Gallstones in patients with hemolysis, b) the structures of the species involved, and c) what other metals participate in the formation of the stones. Methods/Materials Materials: Bilirubin (BR), Copper, Zinc and Calcium salts, Potass...

We report the generation and characterization of an intermediate in a mutant form of the toluene/o-xylene monooxygenase hydroxylase component from Pseudomonas stutzeri OX1. The reaction of chemically reduced I100W variant in the presence of the coupling protein, ToMOD, with dioxygen was monitored by stopped-flow UV/visible spectroscopy. Rapid-freeze quench (RFQ) samples were also generated for ...

Electron paramagnetic resonance (EPR) spectroscopy has increasingly been applied for the study of nucleic acid structure and dynamics. Such studies require incorporation of free radicals (spin labels) into the biopolymer. The labels can be incorporated during chemical synthesis of the oligomer (phosphoramidite approach) or postsynthetically, by reaction of a spin-labeling reagent with a reactiv...

Electron paramagnetic resonance (EPR) spectroscopy was used to record the content of nitric oxide (NO) and copper in brain tissues (frontal lobes hippocampus) liver healthy rats after ischemia modeling. Ischemia simulated by ligation carotid arteries, followed taking 3 ml blood from common artery. Signals triple complexes (DETC) were recorded EPR (DETC)2-Fe2+-NO Cu(DETC)2. Based on direct measu...

It is shown that high-frequency electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) spectroscopy are excellent tools for the investigation of the electronic properties of semiconductor quantum dots (QDs). The great attractions of these techniques are that, in contrast to optical methods, they allow the identification of the dopants and provide information about t...

Rhodothermus marinus, a thermohalophilic gram negative bacterium, contains a type I NADH/quinone oxidoreductase (complex I). Its purification was optimized, yielding large amounts of pure and active protein. Furthermore, the stoichiometry of NADH oxidation and quinone reduction was shown to be 1:1. The large amounts of protein enabled a thorough characterization by electron paramagnetic resonan...

Ternary copper(II) complexes containing bi and tridentate polyamine ligands, viz. [Cu(dien)(en)](ClO4)2 (1), [Cu(dien)(temed)](ClO4)2 (2) and [Cu(pmdt)(temed)](ClO4)2 (3) where dien = diethylenetriamine, en = ethylenediamine, temed = N,N,N′,N′-tetramethylethylenediamine and pmdt = N,N,N′,N′,N′′-pentamethyldiethylenetriamine have been synthesized and characterized by elemental analysis, magnetic...

The observation of the fate of free radicals coming from food after oral administration could be important in evaluating their reactivity in vivo. The aim of this study was to demonstrate that it is feasible to detect directly in vivo free radicals coming from food with the use of low frequency electron paramagnetic resonance (EPR) spectroscopy. Because polyphenols are easily oxidized into stab...

A set of oxime carbamates having N-alkyl and N,N-dialkyl substituents were prepared via carbonyldiimidazole intermediates. It was shown by EPR spectroscopy that they underwent clean homolysis of their N-O bonds upon UV photolysis. During photolysis of acetophenone O-allylcarbamoyl oxime, the corresponding oxazolidin-2-onylmethyl radical was detected by EPR spectroscopy, providing the first evid...