Calcium ion binding by thymocyte plasma membranes

The equilibrium in calcium ions binding to isolated cattle thymocyte plasma membranes within the concentration range 1.10(-5)--5.10(-4) M has been investigated. The plasma membranes has been shown to possess two kinds of Ca(2+)-binding sites with the association constants 2,35.10(5) and 7.64.10(2) M-1 and numbers of binding sites 3.45.10(-4) and 4.55.10(-3) mole.g-1 protein respectively.