Vitamin D-dependent calcium-binding protein from rat kidney.

A calcium-binding protein has been partially purified from rat kidney. It is found in the cortex, but not in the medulla. It is Vitamin D-dependent, as it occurs in normal, but not in Vitamin D-deficient rats. The molecular weight is 28 000, more than twice that of the Vitamin D-dependent calcium-binding proteins from rat intestinal mucosa. The apparent dissociation constant of the partially purified renal calcium-binding protein is approx. 10-5 M.