X-ray crystal structure of eptifibatide bound to human αIIbβ3. Crystal structure is based on published data of eptifibatide docked into the ligand pocket of the extracellular head of human αIIbβ3.¹⁶  In both panels, the eptifibatide molecule is shown in yellow. The white sphere represents crystal water; green sphere, magnesium ion. (A) This image focuses on Asp159 and shows no direct interaction with the eptifibatide. (B) This image focuses on Asp232 and shows that its interaction with eptifibatide is through a water molecule.