From (+)-epigallocatechin gallate to a simplified synthetic analogue as a cytoadherence inhibitor for P. falciparum
作者:Sandra Gemma、Simone Brogi、Pradeep R. Patil、Simone Giovani、Stefania Lamponi、Andrea Cappelli、Ettore Novellino、Alan Brown、Matthew K. Higgins、Khairul Mustafa、Tadge Szestak、Alister G. Craig、Giuseppe Campiani、Stefania Butini、Margherita Brindisi
DOI:10.1039/c3ra45933k
日期:——
Parasite derived surface antigen PfEMP1 is a virulence factor of the human malaria parasite. PfEMP1 variants have been implicated in the cytoadherence of P. falciparum infected erythrocytes (iRBC) to several binding receptors on host vascular endothelium. Among them, binding to ICAM-1 seems to be related to severe manifestations of the disease such as cerebral malaria. The binding site for iRBC has been mapped to the BED-side of the N-terminal immunoglobulin-like domain of ICAM-1, and the DE-loop appears to be critical for binding. To date (+)-EGCG is the unique small molecule anti-cytoadherence inhibitor probably mimicking the DE-loop of ICAM-1. Here we report the discovery of a tetrahydroisoquinoline derivative, a prototype of a novel class of cytoadherence inhibitors, and an analogue of the natural compound characterized by a synthetically accessible scaffold. Molecular modeling analysis of (+)-EGCG and its synthetic tetrahydroisoquinoline analogue rationalized their binding mode to PfEMP1, confirming their ability to mimic the DE-loop.
寄生虫表面抗原 PfEMP1 是人类疟原虫的致病因子。PfEMP1变体与恶性疟原虫感染的红细胞(iRBC)与宿主血管内皮上的几种结合受体的细胞粘附有关。其中,与 ICAM-1 的结合似乎与脑疟疾等疾病的严重表现有关。iRBC 的结合位点已被绘制到 ICAM-1 N 端免疫球蛋白样结构域的 BED 侧,DE 环似乎是结合的关键。迄今为止,(+)-EGCG 是唯一可能模拟 ICAM-1 DE 环的小分子抗细胞粘附抑制剂。在此,我们报告了一种四氢异喹啉衍生物的发现,它是一类新型细胞粘附抑制剂的原型,也是一种天然化合物的类似物,其特点是具有可合成的支架。(+)-EGCG及其合成四氢异喹啉类似物的分子建模分析合理地解释了它们与PfEMP1的结合模式,证实了它们模拟DE环的能力。