Transport of calcium, magnesium and strontium by human serum proteins.

The association constant and the maximal binding capacity for calcium, magnesium and strontium to human serum proteins were determined using a wide concentration range by a dialysis technique. The association curves are similar for these elements. Each curve may be subdivided in three parts: the first would correspond to the subfraction tightly bound to protein, the second one shows a linear design implying the association of the element to different binding points which have the same association constant, and the third part shows the saturation of proteins, which is achieved by alkaline-earth concentration about 9 times higher than the physiological ones.