A Better Fit. An improved anticoagulant drug called RUC-2 (ball and stick structure) fits snugly into its binding pocket on integrin (blue), a protein found on the surface of platelets. RUC-2 binds both subunits of integrin, inhibiting the excessive blood coagulation that can lead to strokes and heart attacks. Unlike similar drugs that alter integrin's structure when they bind and trigger unwanted immune responses, RUC-2 does not disturb the configuration of its larger partner.
See: Structure-Guided Design of a High-Affinity Platelet Integrin αIIbβ3 Receptor Antagonist That Disrupts Mg2+ Binding to the MIDAS by Jieqing Zhu, Won-Seok Choi, Joshua G. McCoy, Ana Negri, Jianghai Zhu, Sarasija Naini, Jihong Li, Min Shen, Wenwei Huang, Daniel Bougie, Mark Rasmussen, Richard Aster, Craig J. Thomas, Marta Filizola, Timothy A. Springer and Barry S. Coller in the Science Translational Medicine, 2012, 4(125), 125ra32. [CREDIT: C. BICKEL/SCIENCE TRANSLATIONAL MEDICINE].