Furukawa Atsushi, Shuchi Yusuke, Wang Jiaqi, Guillen-Poza Pablo Adrian, Ishizuka Shigenari, Kagoshima Misuzu, Ikeno Risa, Kumeta Hiroyuki, Yamasaki Sho, Matsumaru Takanori, Saitoh Takashi, Maenaka Katsumi
Laboratory of Biomolecular Science, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan; Faculty of Pharmaceutical Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa 920-1192, Japan.
Laboratory of Biomolecular Science, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan.
Structure. 2023 Sep 7;31(9):1077-1085.e5. doi: 10.1016/j.str.2023.05.018. Epub 2023 Jun 21.
Mincle (macrophage-inducible C-type lectin, CLEC4E) is a C-type lectin immune-stimulatory receptor for cord factor, trehalose dimycolate (TDM), which serves as a potent component of adjuvants. The recognition of glycolipids by Mincle, especially their lipid parts, is poorly understood. Here, we performed nuclear magnetic resonance analysis, revealing that titration of trehalose harboring a linear short acyl chain showed a chemical shift perturbation of hydrophobic residues next to the Ca-binding site. Notably, there were split signals for Tyr201 upon complex formation, indicating two binding modes for the acyl chain. In addition, most Mincle residues close to the Ca-binding site showed no observable signals, suggesting their mobility on an ∼ ms scale even after complex formation. Mutagenesis study supported two putative lipid-binding modes for branched acyl-chain TDM binding. These results provide novel insights into the plastic-binding modes of Mincle toward a wide range of glycol- and glycerol-lipids, important for rational adjuvant development.
微小C型凝集素（巨噬细胞诱导性C型凝集素，CLEC4E）是一种针对索状因子——海藻糖二霉菌酸酯（TDM）的C型凝集素免疫刺激受体，TDM是佐剂的一种有效成分。微小C型凝集素对糖脂的识别，尤其是对其脂质部分的识别，目前还了解甚少。在此，我们进行了核磁共振分析，结果显示，携带线性短酰基链的海藻糖滴定显示，钙结合位点旁边的疏水残基发生了化学位移扰动。值得注意的是，在形成复合物后，酪氨酸201出现了分裂信号，表明酰基链存在两种结合模式。此外，大多数靠近钙结合位点的微小C型凝集素残基没有显示出可观察到的信号，这表明即使在形成复合物后，它们在约毫秒的时间尺度上仍具有流动性。诱变研究支持了分支酰基链TDM结合的两种推定脂质结合模式。这些结果为微小C型凝集素对多种糖脂和甘油脂质的可塑性结合模式提供了新的见解，这对合理开发佐剂具有重要意义。
