The vitamin K-dependent proteins.

A new class of proteins has emerged, the so-called vitamin K-dependent calcium binding proteins, which are uniquely characterized by the presence of alpha-carboxyglutamic acid residues. These proteins have been identified in a variety of tissues and body fluids. The specialized nature of calcium binding by Gla residues promotes protein phospholipid interaction, which is important not only in blood coagulation but in many tissue processes involving calcium metabolism. What role other than the blood coagulation mechanism the vitamin K reaction may play in diseases in children is still unclear.