The ligands of certain G-protein-coupled receptors (GPCRs) have been identified as endogenous lipids, such as lysophosphatidylserine (LysoPS). Here, we analyzed the molecular basis of the structure–activity relationship of ligands of GPR34, one of the LysoPS receptor subtypes, focusing on recognition of the long-chain fatty acid moiety by the hydrophobic pocket. By introducing benzene ring(s) into the fatty acid moiety of 2-deoxy-LysoPS, we explored the binding site’s preference for the hydrophobic shape. A tribenzene-containing fatty acid surrogate with modifications of the terminal aromatic moiety showed potent agonistic activity toward GPR34. Computational docking of these derivatives with a homology modeling/molecular dynamics-based virtual binding site of GPR34 indicated that a kink in the benzene-based lipid surrogates matches the L-shaped hydrophobic pocket of GPR34. A tetrabenzene-based lipid analogue bearing a bulky tert-butyl group at the 4-position of the terminal benzene ring exhibited potent GPR34 agonistic activity, validating the present hydrophobic binding pocket model.

中文翻译：

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通过对接辅助结构-活性分析探讨G蛋白偶联的溶血磷脂酰丝氨酸受体GPR34 / LPS ₁的疏水结合口袋。

某些G蛋白偶联受体（GPCR）的配体已被鉴定为内源性脂质，例如溶血磷脂酰丝氨酸（LysoPS）。在这里，我们分析了LysoPS受体亚型之一的GPR34配体的结构-活性关系的分子基础，重点是疏水口袋对长链脂肪酸部分的识别。通过将苯环引入2-脱氧的脂肪酸部分-LysoPS，我们探索了结合位点对疏水形状的偏好。具有末端芳族部分的修饰的含三苯的脂肪酸替代物显示出对GPR34的有效激动活性。这些衍生物与基于GPR34的同源性建模/基于分子动力学的虚拟结合位点的计算对接表明，基于苯的脂质替代物中的纽结与GPR34的L形疏水口袋相匹配。在末端苯环的4-位带有庞大的叔丁基的基于四苯的脂质类似物表现出强效的GPR34激动活性，证实了本发明的疏水结合口袋模型。