Prothrombin undercarboxylated

In the case of prothrombin and related clotting factors, interruption of the vitamin K cycle leads to the production of nonfunctional, undercarboxylated proteins, which are duly exported from hepatocytes into blood (Thijssen 1995). They are nonfunctional because there is a requirement for the additional carboxyl residues in the clotting process. Ionized carboxyl groups can establish links with negatively charged sites on neighboring phospholipid molecules of cell surfaces via calcium bridges. 

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