A New Phenylalanine Derivative Acts as an Antagonist at the AMPA Receptor GluA2 and Introduces Partial Domain Closure: Synthesis, Resolution, Pharmacology, and Crystal Structure
作者:Ewa Szymańska、Karla Frydenvang、Alberto Contreras-Sanz、Darryl S. Pickering、Elena Frola、Zorica Serafimoska、Birgitte Nielsen、Jette S. Kastrup、Tommy N. Johansen
DOI:10.1021/jm200862h
日期:2011.10.27
In order to map out molecular determinants for competitive blockade of AMPA receptor subtypes, a series of 2-carboxyethylphenylalanine derivatives has been synthesized and pharmacologically characterized in vitro. One compound in this series, (RS)-3h, showed micromolar affinity for GluA1(o). and GluA2(R)(o) receptors with an approximately 4-fold preference for GluA1/2 vs GluA3/4. In TEVC electrophysiological experiments (RS)-3h competitively antagonized GluA2(Q)(i) receptors. The X-ray structure of the active enantiomer (S)-3h in complex with GluA2-S1S2J showed a domain closure around 8 degrees. Even though the nitro and the carboxyethyl groups of (S)-3h were both anchored to Tyr702 through a water H-bond network, these interactions only induced weak subtype selectivity. In spite of the fact that (S)-3h induced a domain closure close to that observed for partial agonists, it did not produce agonist responses at GluA2 receptors under nondesensitizing conditions. 2-Carboxyethylphenylalanine derivatives provide a new synthetic scaffold for the introduction of substituents that could lead to AMPA receptor subtype-selective ligands.