Properties of Calcium-Binding Protein isolated from the Soluble Fraction of Normal Rat Liver

Abstract

The molecular weight of calcium-binding protein (CaBP) purified from the soluble fraction of normal rat liver was estimated to be 28800 by calibrated gel filtration on Sephadex G-100. Amino acid analysis of the CaBP showed glycine and glutamic acid to be the predominant amino acids. The calcium binding constant was found to be 4.19×10⁵M^-1 by equilibrium dialysis, and there appear to be 6-7 high affinity binding sites for calcium per molecule of protein.