A novel series of dimeric melatonin analogues obtained by connecting two melatonin molecules through N1 with spacers of 15–24 atoms was synthesized and characterized in 2-[125-I]-iodomelatonin binding and bioluminescence resonance energy transfer (BRET) experiments at MT1 and MT2 receptors. Compounds 4 (16 atoms spacer) and 13 (24 atoms spacer) are among the ligands inducing the maximal BRET at MT2-homodimers as well as at both types of MT1/MT2 heterodimers. Notably, ligand-induced BRET changes observed for compounds linked through spacers of 22–24 atoms could be attributed to ligand-induced conformational changes between the two protomers of MT1 and MT2 homo- and heterodimers providing evidence for the binding of both pharmacophores of dimeric melatonin analogues to the two protomers of receptor dimers.
合成并表征了一系列通过N1连接两个
褪黑激素分子的二聚体
褪黑激素类似物,连接的间隔原子数为15–24。在
MT1和
MT2受体的2-[125-I]-
碘褪黑激素结合和
生物发光共振能量转移(BRET)实验中,对这些化合物进行了表征。化合物4(16个原子间隔)和化合物13(24个原子间隔)是能够在
MT2同源二聚体以及两种类型的
MT1/
MT2异源二聚体中诱导最大BRET的
配体。值得注意的是,观察到的通过22-24个原子间隔连接的化合物诱导的BRET变化,可以归因于
配体诱导的
MT1和
MT2同源及异源二聚体两个原份子之间的构象变化,这为二聚体
褪黑激素类似物双药效团与受体二聚体两个原份子的结合提供了证据。