Inhibition of Ca2+-pump ATPase and the Na+/K+-pump ATPase by iron-generated free radicals

Preincubation of red blood cell (RBC) membranes with a model system known to generate reactive oxygen species (ROS) and free radicals (200 μM ferrous sulfate and 200 μM EDTA, Fe2+/EDTA) resulted in inhibition of the Na+K+-pump ATPase, the basal Ca2+-pump ATPase, and the calmodulin-activated Ca2+-pump ATPase. Inhibition of the ion pump ATPases was also associated with membrane protein crosslinking and lipid peroxidation, the latter as monitored...