ADAMTS13

ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13)—also known as von Willebrand factor-cleaving protease (VWFCP)—is a zinc-containing metalloprotease enzyme that cleaves von Willebrand factor (vWf), a large protein involved in blood clotting. It is secreted in blood and degrades large vWf multimers, decreasing their activity.

Genetics

The ADAMTS13 gene maps to the ninth chromosome (9q34).

Discovery

Since 1982 it had been known that thrombotic thrombocytopenic purpura (TTP), one of the microangiopathic hemolytic anemias (see below), was characterized in its familial form by the presence in plasma of unusually large von Willebrand factor multimers (ULVWF).

In 1994, vWF was shown to be cleaved between a tyrosine at position 1605 and a methionine at 1606 by a plasma metalloprotease enzyme when it was exposed to high levels of shear stress. In 1996, two research groups independently further characterized this enzyme. In the next two years, the same two groups showed that the congenital deficiency of a vWF-cleaving protease was associated with formation of platelet microthrombi in the small blood vessels. In addition, they reported that IgG antibodies directed against this same enzyme caused TTP in a majority of non-familial cases.