Studies on Dihydroorotate Dehydrogenase by Electron Paramagnetic Resonance Spectroscopy

Studies on dihydroorotate dehydrogenase by electron paramagnetic resonance spectroscopy. II. Electron paramagnetic resonance and optical spectra and titrations.

When dihydroorotate dehydrogenase, from Zymobacterium oroticum, was reduced by DPNH or dihydroorotate and examined by electron paramagnetic resonance spectrometry, a relatively intense free radical signal and the asymmetric signal at g = 1.94, found in many nonheme iron proteins, were observed within a few milliseconds. Both shape and saturation with microwave power of the free radical signals ...

Kinetic Studies on Reduced Diphosphopyridine Nucleotide Dehydrogenase by Electron Paramagnetic Resonance Spectroscopy*

Studies by means of electron paramagnetic resonance spectroscopy on animal tissues and mitochondria (1, 2), on a variety of microbes (3), and on enzymes derived from these sources (4-7) have revealed an apparently new component in these materials, which is recognized by a characteristic signal (g = 1.94) seen only under reducing conditions. The signal was provisionally attributed to a reduced f...

Electron Paramagnetic Resonance Spectroscopy

Demystifying EPR: A Rookie Guide to the Application of Electron Paramagnetic Resonance Spectroscopy on Biomolecules

Electron Paramagnetic Resonance (EPR) spectroscopy, also known as Electron Spin Resonance(ESR) especially among physicists, is a strong and versatile spectroscopic method forinvestigation of paramagnetic systems, i.e. systems like free radicals and most transition metalions, which have unpaired electrons. The sensitivity and selectivity of EPR are notable andintriguing as compared to other spec...

Studies of aldehyde oxidase by electron paramagnetic resonance spectroscopy. II. Kinetic studies by rapid freezing.

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...