Acrylamide-derived compounds have been previously shown to act as modulators of members of the Cys-loop transmitter-gated ion channel family, including the mammalian GABA_A receptor. Here we have synthesized and functionally characterized the GABAergic effects of a series of novel compounds (termed "DM compounds") derived from the previously characterized GABA_A and the nicotinic α7 receptor modulator (E)-3-furan-2-yl-N-p-tolyl-acrylamide (PAM-2). Fluorescence imaging studies indicated that the DM compounds increase apparent affinity to the transmitter by up to 80-fold in the ternary αβ GABA_A receptor. Using electrophysiology, we show that the DM compounds, and the structurally related (E)-3-furan-2-yl-N-phenylacrylamide (PAM-4), have concurrent potentiating and inhibitory effects that can be isolated and observed under appropriate recording conditions. The potentiating efficacies of the DM compounds are similar to those of neurosteroids and benzodiazepines (G ~ –1.5 kcal/mol). Molecular docking, functionally confirmed by site-directed mutagenesis experiments, indicate that receptor potentiation is mediated by interactions with the classic anesthetic binding sites located in the transmembrane domain of the intersubunit interfaces. Inhibition by the DM compounds and PAM-4 was abolished in the receptor containing the α1(V256S) mutation, suggestive of similarities in the mechanism of action with that of inhibitory neurosteroids. Functional competition and mutagenesis experiments, however, indicate that the sites mediating inhibition by the DM compounds and PAM-4 differ from those mediating the action of the inhibitory steroid pregnenolone sulfate.

丙烯酰胺衍生化合物先前已被证明可作为 Cys 环递质门控离子通道家族成员（包括哺乳动物 GABA _A受体）的调节剂。在此，我们合成了一系列新型化合物（称为“DM 化合物”），并对其 GABA 作用进行了功能表征，这些化合物源自先前表征的 GABA _A和烟碱α 7 受体调节剂 (E)-3-呋喃-2-基- N -对甲苯基丙烯酰胺（PAM-2）。荧光成像研究表明，DM 化合物将三元αβ GABA _A中与递质的表观亲和力提高了 80 倍受体。利用电生理学，我们证明 DM 化合物和结构相关的 (E)-3-呋喃-2-基-N-苯基丙烯酰胺 (PAM-4) 具有同时的增强和抑制作用，可以在适当的记录下分离和观察到这些作用状况。DM 化合物的增强功效与神经类固醇和苯二氮卓类药物 (G ~ –1.5 kcal/mol) 相似。通过定点诱变实验在功能上证实的分子对接表明，受体增强是通过与位于亚基间界面的跨膜结构域中的经典麻醉剂结合位点的相互作用介导的。DM 化合物和 PAM-4 的抑制在含有α 的受体中被消除1(V256S) 突变，表明其作用机制与抑制性神经类固醇相似。然而，功能竞争和诱变实验表明，介导DM化合物和PAM-4抑制的位点与介导抑制性类固醇孕烯醇酮硫酸盐作用的位点不同。