The crystal structure of dimeric Fe(III) superoxide dismutase (SOD) from Escherichia coli (3006 protein atoms, 2 irons, and 281 solvents) has been refined to an R of 0.184 using all observed data between 40.0 and 1.85 A (34,879 reflections). Features of this structure are compared with the refined structure of MnSOD from Thermus thermophilus. The coordination geometry at the Fe site is distorte...

Hangman Fe(III) corroles catalyse H(2)O(2) disproportionation at a faster rate and display a more pronounced hangman effect than their one electron oxidized analogues owing to their ability to bypass high energy intermediates by redox-leveling derived from the use of the corrole as a non-innocent ligand.

In this review we provide an analysis of the biochemistry of peroxynitrite and tyrosine nitration. Peroxynitrite is the product of the diffusion-controlled reaction between superoxide (O2•-) and nitric oxide (•NO). This process is in competition with the enzymatic dismutation of O2•- and the diffusion of •NO across cells and tissues and its reaction with molecular targets (e.g. guanylate cyclas...

The xylene ring of riboflavin originates by dismutation of the precursor, 6,7-dimethyl-8-ribityllumazine. The formation of the latter compound requires a 4-carbon unit as the precursor of carbon atoms 6 alpha, 6, 7, and 7 alpha of the pyrazine ring. The formation of riboflavin from GTP and ribose phosphate by cell extract from Candida guilliermondii has been observed by Logvinenko et al. (Logvi...

In the course of histochemical studies of the retina, it was desired to determine the diphosphopyridine nucleotide content of single microtome sections of tissue weighing on the order of 10 to 50 y. It was, therefore, necessary to increase the sensitivity of the manometric method for the determination of DPN. To this end, the technique of Linderstrom-Lang (6) with the Cartesian diver was employ...

Most of the oxygen consumed by aerobic organisms is reduced to water by the enzyme cytochrome c oxidase in the terminal reaction of the mitochondrial respiratory chain. Since oxygen in the ground state is in a triplet configuration (with two unpaired electrons in the outer shell) its reduction to water must occur in four consecutive one-electron steps. Some of the partially reduced oxygen inter...

Control of the intraphagosomal pH in neutrophils may be of importance in creating a microbicidal environment by regulating the activity of the O2-.-generating NADPH oxidase and the lysosomal enzymes discharged into this compartment. In this study, we examined the proton stoichiometry associated with the primary enzymatic reaction underlying the respiratory burst. A preparation of the neutrophil...