A defined deletion in the Escherichia coli K-12 sodA gene (encoding manganese-superoxide dismutase) linked to a nontransposable selectable marker was generated by transposon Tn5 insertion in combination with in vitro mutagenesis. This mutant allele was used to replace the wild-type sodA gene in an E. coli clinical isolate of serotype O18ac:K1:H7 by bacteriophage P1 transduction. The O18ac:K1:H7...

A high degree of lipid oxidative damage was detected in manganese-deficient lignin peroxidase (LIP)-producing cultures of Phanerochaete chrysosporium, indicating intensive exposure to high concentrations of reactive oxygen species (ROS), as is typically found in oxygenated LIPproducing cultures. The absence of manganese ions (Mn2+) in the cultures prevented activation of the manganese-containin...

The phototrophic bacterium Rhodobacter capsulatus contains a single, oxygen-responsive superoxide dismutase (SOD(Rc)) homologous to iron-containing superoxide dismutase enzymes. Recombinant SOD(Rc), however, displayed higher activity after refolding with Mn(2+), especially when the pH of the assay mixture was raised. SOD(Rc) isolated from Rhodobacter cells also preferentially contains manganese...

Based on the concept that activated oxygen species are causally involved in Adriamycin toxicity, endogenous antioxidant defenses are expected to be important determinants of cellular Adriamycin tolerance. We have tested this prediction by making use of an oxygen-resistant variant subline of Chinese hamster ovary cells (CHOr), which is characterized by increased levels of glutathione, copper- an...

Superoxide dismutase (SOD, EC 1.15.1.1) plays an important antioxidant defense role in skins exposed to oxygen. We studied the inhibitory effects of Al(3+) on the activity and conformation of manganese-containing SOD (Mn-SOD). Mn-SOD was significantly inactivated by Al(3+) in a dose-dependent manner. The kinetic studies showed that Al(3+) inactivated Mn-SOD follows the first-order reaction. Al(...

Superoxide dismutase is antioxidant enzyme responsible for the quenching of superoxide radicals which are released during the chemical reactions of the various metabolic pathways. It is a non-heme protein. Different iso-enzymes of superoxide dismutase are described. The mitochondrial enzyme is manganese dependent, cytoplasmic enzyme is copper-zinc dependent. These enzymes are evenly and ubiquit...

Gross overproduction of the manganese-containing superoxide dismutase in Escherichia coli, by virtue of a multicopy plasmid bearing the sodA gene, decreases enumeration on paraquat-containing agar plates. This reflects growth inhibition, not lethality, since cells on these plates can be rescued by exclusion of dioxygen. Growth in liquid medium revealed that the control strain adapted to growth ...

Superoxide dismutases' (SODs) expression is altered in several diseases including Alzheimer, atherosclerosis, cancer and psoriasis. Previously, we reported a marked increase in Mn-SOD and Cu,Zn-SOD functional activity in human dermal psoriatic fibroblasts. As retinoic acid (RA) has been used in the treatment of psoriasis and a mechanism for its beneficial effects is not understood, we investiga...