FRETS-VWF73: Fluorescence-Quenching Substrate for ADAMTS-13

Thrombotic thrombocytopenic purpura (TTP) is a rare and potentially fatal blood condition characterized by the formation of microvascular thrombi. Until recently the cause of TTP remained elusive. Latest research points to the involvement of a protein in the plasma called von Willebrand factor (vWF). vWF is an extremely large molecule that is able to bind to platelets or to injured blood vessel lining and is a normal component of plasma that is required for blood clotting. vWF molecules are rather sticky and are usually found circulating in the blood. Normally, they are broken down to slightly smaller sizes so that vWF retains its adhesive properties without binding inappropriately, leading to undesired blood clots. von Willebrand disease is an inherited condition characterized by excessive bleeding and is due to lack of vWF. In TTP, vWF is synthesised normally but its cleavage is defective. This is considered to be due to the lack of enzyme activity called vWF cleaving protease. The vWF cleaving protease has been reported to be a new member of the ADAMTS family of metalloproteases, designated as ADAMTS-13.

Currently, there is no specific test to confirm the diagnosis of this potentially fatal condition. A new fluorescent-quenching substrate is now available from the Peptide Institute and Peptides International. This ADAMTS-13 specific  substrate should be a valuable tool to aid in the discovery of diagnostic markers for TTP.

Authors from Peptides International