National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
1R01GM120553
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
T32GM008268
米国
引用
ジャーナル: Structure / 年: 2017 タイトル: The Therapeutic Antibody LM609 Selectively Inhibits Ligand Binding to Human αβ Integrin via Steric Hindrance. 著者: Andrew J Borst / Zachary M James / William N Zagotta / Mark Ginsberg / Felix A Rey / Frank DiMaio / Marija Backovic / David Veesler / 要旨: The LM609 antibody specifically recognizes αβ integrin and inhibits angiogenesis, bone resorption, and viral infections in an arginine-glycine-aspartate-independent manner. LM609 entered phase II ...The LM609 antibody specifically recognizes αβ integrin and inhibits angiogenesis, bone resorption, and viral infections in an arginine-glycine-aspartate-independent manner. LM609 entered phase II clinical trials for the treatment of several cancers and was also used for αβ-targeted radioimmunotherapy. To elucidate the mechanisms of recognition and inhibition of αβ integrin, we solved the structure of the LM609 antigen-binding fragment by X-ray crystallography and determined its binding affinity for αβ. Using single-particle electron microscopy, we show that LM609 binds at the interface between the β-propeller domain of the α chain and the βI domain of the β chain, near the RGD-binding site, of all observed integrin conformational states. Integrating these data with fluorescence size-exclusion chromatography, we demonstrate that LM609 sterically hinders access of large ligands to the RGD-binding pocket, without obstructing it. This work provides a structural framework to expedite future efforts utilizing LM609 as a diagnostic or therapeutic tool.