Complement component 3a receptor 1 (C3aR) is an anaphylatoxin receptor that mediates inflammatory processes. Although considerable effort has gone into discovering the antagonists and agonists of C3aR, structural insights are required to search for effective ligands and to elucidate their binding modes and the mechanism of activation and inactivation. No experimental structural data of C3aR have yet been reported. We investigated the binding mode of an antagonist of C3aR using a combination of homology modeling, ligand docking, molecular dynamics simulations, and binding free energy calculations. We produced a plausible binding model consistent with the reported experimental data. We believe that this model is appropriate for the identification of new C3aR antagonists, as it can distinguish between antagonists and decoy compounds.

补体成分3a受体1（C3aR）是介导炎症过程的过敏毒素受体。尽管已经为发现C3aR的拮抗剂和激动剂付出了巨大的努力，但是需要结构上的见识来寻找有效的配体并阐明其结合模式以及激活和失活的机制。尚未报道C3aR的实验结构数据。我们使用同源性建模，配体对接，分子动力学模拟和结合自由能计算的组合研究了C3aR拮抗剂的结合模式。我们产生了与报道的实验数据一致的合理的结合模型。我们认为该模型适用于鉴定新的C3aR拮抗剂，因为它可以区分拮抗剂和诱饵化合物。