Human thrombin (IMAGE) University of Tokyo Caption Thrombin is the enzyme responsible for bleeding and for blood clotting, depending on how it’s activated, and has two DNA drug-binding sites. Credit ©2023 Yoshimoto et al. CC-BY Usage Restrictions Credit must be given to the creator. License CC BY Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.