what is prothrombin
Prothrombin. Prothrombin is a blood-clotting protein. Injury to a blood vessel produces a signal which triggers the conversion of prothrombin to thrombin. Thrombin is a protein which plays a central role in provoking the assembly of other proteins to form the blood clot.rothrombin consumption test a test to measure the formation of intrinsic thromboplastin by determining the residual serum prothrombin after blood clotting is complete.