A previously developed spectrometer for broadband electron paramagnetic resonance (EPR) spectroscopy of dilute randomly oriented systems has been considerably modified to extend the frequency reach down hundred MHz range and boost concentration sensitivity by 1 2 orders magnitude. The instrument is now suitable study biological in particular metalloproteins. As a proof concept, examples from cl...

The electron paramagnetic resonance absorption of nitric oxide hemoglobin was observed as a possible model system for oxyhemoglobin. The electron paramagnetic resonance spectrum showed three g factors indicating a rhombic symmetry around the paramagnetic center. By use of 15N0, the unpaired electron was found very little associated with NO nitrogen, in contrast to what has been customarily assu...

A rapid increase in RNA structural studies has been seen in the past few years, in part due to the interest in the multitude of cellular functions performed by RNA. Electron paramagnetic resonance spectroscopy is a useful technique for studying biopolymer structure under physiologically relevant conditions. We present herein the use of pulsed electron double resonance for the determination of a...

Electron Paramagnetic Resonance (EPR) spectroscopy is the method of choice to study paramagnetic cofactors that often play an important role as active centers in electron transfer processes in biological systems. However, in many cases more than one paramagnetic species is contributing to the observed EPR spectrum, making the analysis of individual contributions difficult and in some cases impo...

The paramagnetic effect of Mn2+ on the electron paramagnetic resonance spectrum of a nitroxide spin label covalently attached to the active-site serine residue of des-1-41-light chain bovine plasma-activated protein C, and situated at a distance of approximately 1.2 nm from this amino acid, has been utilized to estimate the distance on the enzyme surface between the single Mn2+ site and the fre...

A 16-line pattern has been theoretically predicted, but hitherto not reported, for the Electron Paramagnetic Resonance (EPR) spectrum of antiferromagnetically coupled CuII triangles experiencing isotropic exchange isosceles magnetic symmetry.

Electron spin resonance (ESR), called also electron paramagnetic resonance (EPR) together with the spin trapping technique, has allowed us to study and understand how free radicals are involved in various pathologies. In this review, the importance of spin trapping technique in the study of diseases such as cancer, diabetes, hypertension and parasitic diseases is discussed. In addition, advance...

The reactions of three α-oxoaldehydes (methylglyoxal, glyoxal, and pyruvic acid) with hydroxyl radicals generated by sonolysis of water were investigated using an electron spin resonance (electron paramagnetic resonance) spin-trapping method, and their reaction kinetics were investigated. It is apparent from our experimental results that methylglyoxal exhibits the highest reactivity of the thre...