Glutathione-dependent conversion of ferryl leghaemoglobin into the ferric form: a potential protective process in soybean (Glycine max) root nodules.

GSH is able to reduce soybean (Glycine max) ferryl-leghaemoglobin [Lb(IV)] formed by the reaction of ferric or ferrous Lb with H2O2; in both cases, ferric Lb is obtained and GSH is incapable of reducing ferric Lb to ferrous Lb. Furthermore, the addition of GSH before H2O2 to ferric Lb prevents side reactions which lead to a species whose spectrum differs markedly from that of Lb(IV). These reactions are likely to occur in vivo, as high GSH concentrations have been detected in soybean nodules.

Characterization and properties of Pholas luciferase as a metalloglycoprotein.

The luciferase of the bioluminescent boring mollusc, Pholas dactylus, has been purified by a new method which includes centrifugation in cesium chloride gradients. Homogeneous preparations have been obtained and molecular weight determinations and subunit analysis support the idea that this preparation is an oxyluciferin-luciferase complex. The preparation catalyzes oxidation of ascorbic acid in presence of H2O2, and this peroxidase activitity has been used for characterization (thermal and pH stabilities, activity as a function of pH, isoelectric point, turnover number).