Positive allosteric modulators (PAMs) of nicotinic acetylcholine receptors (nAChR) are important therapeutic candidates as well as valuable research tools. We identified a novel type II PAM, (R)-7-bromo-N-(piperidin-3-yl)benzo[b]thiophene-2-carboxamide (Br-PBTC), which both increases activation and reactivates desensitized nAChRs. This compound increases acetylcholine-evoked responses of α2* and α4* nAChRs, but is without effect on α3* or α6* nAChRs ("*" indicates presence of other nAChR subunits). Br-BPTC binds to the C-terminal extracellular sequences of a4 subunits, which is also a PAM site for steroid hormone estrogens such as 17-β estradiol. Br-PBTC is much more potent than estrogens. Like 17-P-estradiol, the non-steroid Br-PBTC only requires one α4 subunit to potentiate nAChR function, and its potentiation is stronger with more a4 subunits. This feature enables Br-BPTC to potentiate activation of (α4β2)(α6β2)β3 but not (α6β2)2β3 nAChRs. Various bioactive analogs of Br-PBTC are provided.
正向变构调节剂(P
AMs)对
尼古丁乙酰胆碱受体(nAChR)是重要的治疗候选药物,同时也是有价值的研究工具。我们发现了一种新型II型P
AM,(R)-7-
溴-N-(
哌啶-3-基)苯并[b]
噻吩-2-甲酰胺(Br-
PBTC),它既增加了激活,又重新激活了脱敏的nAChRs。这种化合物增加了α2*和α4* nAChRs对
乙酰胆碱的响应,但对α3*或α6* nAChRs没有影响("*"表示存在其他nAChR亚基)。Br-B
PTC结合到α4亚基的C端外胞外序列,这也是类
固醇激素
雌激素如17-β
雌二醇的P
AM位点。Br-
PBTC比
雌激素更有效。与17-β
雌二醇一样,非类
固醇Br-
PBTC只需要一个α4亚基来增强nAChR功能,并且随着更多的α4亚基,其增强作用更强。这个特性使Br-B
PTC能够增强(α4β2)(α6β2)β3而不是(α6β2)2β3 nAChRs的激活。提供了各种
生物活性类似物的Br-
PBTC。