In vitro studies on some parameters of the binding of the rat hemopexin--heme complex with the hepatic membrane receptor

The binding of 125I]Hpx--heme with the rat hepatic plasma membrane receptor was studied at 37 degrees C as well as different parameters such as plasma membrane concentration, calcium dependence, optimal pH and specific binding. A Scatchard plot revealed the existence of one binding for 125I]Hpx--heme on the isolated liver plasma membrane with a Kd = 3.2 X 10(-8) M.