Vitamin D-dependent calcium-binding protein

Vitamin D-dependent calcium binding proteins were discovered in the cytosolic fractions of chicken intestine, and later in mammalian intestine and kidney, by workers including Robert Wasserman of Cornell University.

They bound calcium in the micromolar range and were greatly reduced in vitamin D-deficient animals. Expression could be induced by treating these animals with vitamin D metabolites such as calcitriol.

They were found to exist in two distinct sizes with a molecular weight of approximately 9 kDa and 28 kDa. They were renamed calbindin; calbindin-D9k (S100G) is found in mammalian intestine and calbindin-D28k in avian intestine and in kidney.