The mechanism of the enzymic reaction of an iron-containing superoxide dismutase purified from the marine bacterium Photobacterium leiognathi was studied by using pulse radiolysis. Measurements of activity were done with two different preparations of enzyme containing either 1.6 or 1.15 g-atom of iron/mol. In both cases, identical values of the second-order rate constant for reaction between su...

Reactive oxygen species (ROS) such as superoxide and hydrogen peroxide are known to play an important role in the proliferation and viability of vascular smooth muscle cells. In this study, we determined the effects of increased superoxide dismutase and catalase activity on fetal pulmonary arterial smooth muscle cell (FPASMC) proliferation and viability using EUK-134, a superoxide dismutase/cat...

Heat shock proteins are induced at normal temperatures by oxidants and during reoxygenation following hypoxia. We now report cyanide-resistant O2 consumption increased 30-50% in rat lungs exposed to heat shock or reoxygenation following hypoxia. The synthesis of Cu,Zn superoxide dismutase, but not Mn superoxide dismutase, was increased in rat lung slices by in vivo hyperthermia (39 degrees C), ...

background: superoxide radicals are produced during oxidative metabolic processes, and removed by superoxide dismutase (sod) enzymes. controversial results have been reported regarding the tissue and plasma concentration of sod in patients with breast cancer. methods: venous blood was obtained from study participants and activity of sod enzyme was determined in 100 women. comparison was made be...

Recent studies indicate that oxygen radicals such as superoxide or singlet oxygen may be important in the functional activity of human granulocytes. We have examined the possible importance of these radicals in the functional capacity of human blood monocytes. Monocytes, like granulocytes, generate chemiluminescence during phagocytosis. Chemiluminescence is impaired 50-90% by superoxide dismuta...

The rate constants of the reactions between pulse radiolytically produced superoxide radicals and the Cu(II) chelate of diethyldithiocarbamate were determined at pH 7.0. It was found that diethyldithiocarbamate forms a copper complex, which as no dismutating activity. The removal of the protein bound copper in superoxide dismutase by diethyldithiocarbamate yields the same effect as coordination...

1. Apo-superoxide dismutase was more labile toward a variety of inactivating stresses than was the holoenzyme. 2. cu++ restored catalytic activity to the apoenzyme and markedly enhanced its thermal stability but Cu++ plus Zn++ were needed to attain the stability of the native enzyme. 3. Co’-+ or Hgii were able to replace Zn++ in increasing the thermal stability of the Cu+f-repleted apoenzyme. I...

BACKGROUND: Cancer cachexia is the progressive loss of skeletal muscle protein that contributes significantly to cancer morbidity and mortality. Evidence of antioxidant attenuation and the presence of oxidised proteins in patients with cancer cachexia indicate a role for oxidative stress. The level of oxidative stress in tissues is determined by an imbalance between reactive oxygen species prod...