4MMZ | pdb_00004mmz

• 👁 Image
   Download Mendeley

Structural basis for pure antagonism of integrin alpha V beta 3 by a high-affinity form of fibronectin.

(2014) Nat Struct Mol Biol 21: 383-388

• PubMed: 24658351 Search on PubMedSearch on PubMed Central
• DOI: https://doi.org/10.1038/nsmb.2797
• Primary Citation Related Structures: 
  4MMX, 4MMY, 4MMZ


• PubMed Abstract: 
  

  Integrins are important therapeutic targets. However, current RGD-based anti-integrin drugs are also partial agonists, inducing conformational changes that trigger potentially fatal immune reactions and paradoxical cell adhesion. Here we describe the first crystal structure of αVβ3 bound to a physiologic ligand, the tenth type III RGD domain of wild-type fibronectin (wtFN10), or to a high-affinity mutant (hFN10) shown here to act as a pure antagonist. Comparison of these structures revealed a central π-π interaction between Trp1496 in the RGD-containing loop of hFN10 and Tyr122 of the β3 subunit that blocked conformational changes triggered by wtFN10 and trapped hFN10-bound αVβ3 in an inactive conformation. Removing the Trp1496 or Tyr122 side chains or reorienting Trp1496 away from Tyr122 converted hFN10 into a partial agonist. These findings offer new insights into the mechanism of integrin activation and a basis for the design of RGD-based pure antagonists.

---

Organizational Affiliation: 
• 1] Structural Biology Program, Department of Medicine, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, USA. [2].
Leukocyte Biology and Inflammation Program, Department of Medicine, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, USA.
Structural Biology Program, Department of Medicine, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, USA.
Global Research and Early Development, Translational Innovation Platform, Oncology, Merck KGaA, Darmstadt, Germany.
1] Structural Biology Program, Department of Medicine, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, USA. [2] Leukocyte Biology and Inflammation Program, Department of Medicine, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, USA.