A unique binding epitope for salvinorin A, a non‐nitrogenous kappa opioid receptor agonist
The FEBS Journal May 1, 2006 Brian E. Kane, Marcelo J. Nieto, Christopher R. McCurdy et al.
Salvinorin A, a potent kappa opioid receptor agonist, binds to a specific cluster of residues in transmembrane helices II and VII, including Q115, Y119, Y312, Y313, and Y320, rather than to traditional opioid binding sites. A model is proposed where the ligand aligns vertically between these helices, spanning residues one to two turns down the helix faces. The extracellular loop 2 (EL-2) plays an indirect role in binding and selectivity. These findings clarify the structural basis for salvinorin A's unique binding and selectivity.