[Mechanism of calcium ion transport in brain microsome fractions]

The influence of Ca2+ in rising concentrations on the ATP-dependent Ca2+-binding system of the brain microsome fraction, the inhibitory effect of SH-reagents on it and the protective effect of ATP correlate with the properties of the Mg2+-dependent Ca2+-activated ATPase of this fraction. Such properties of the system as inactivation with an increase in Ca2+-concentration effect of phosphate and oxalate, relation to detergents cannot be explained from the view point of the tri-phosphoinozitid-dependent binding of Ca2+. These data indicate that the general mechanism of Ca2+ transport in the brain microsome fraction is similar to the mechanism of this process in the sarcoplasmatic reticulum and is realized with participation of Mg2+, Ca2+-ATPase.