Mg2+: a potent inhibitor of collagen-induced in vitro mineralization.

At physiological concentrations, Mg2+ has been found to be a potent inhibitor of collagen-induced in vitro mineralization. Mg2+ inhibits mineralization by competing with Ca2+ for specific phosphate independent Ca2+ binding sites of the catalytic matrix. Matrix bound Mg2+ subsequently reacts with HPO4(2-) to form MgHPO4 complex which can not be further converted to the matrix bound mineral phase. The matrix, as well as the mineral phase associated with the matrix, influence the rate of mineralization.