Galectins are a family of β-galactoside binding proteins, and insect galectins play a role in immune responses and may also affect Cry toxin activity. In this study, we aimed to further understand the function and molecular mechanism of Aedes aegypti galectin-6 in modulation of Cry11Aa toxicity. A. aegypti galectin-6 was cloned, and the recombinant galectin-6 was expressed and purified. Bioassays indicated that galectin-6 could reduce the toxicity of Cry11Aa, protecting A. aegypti larvae. To determine interactions among galectin-6, Cry11Aa and putative toxin receptors, Octet Red System, western blotting, far-western blotting and ELISA assays were performed. Octet Red System showed that galectin-6 bound to BBMVs of A. aegypti larvae with lower affinity than that of Cry11Aa. Western blotting and far-western blotting analyses demonstrated that galectin-6 bound to A. aegypti ALP1 and APN2 as well as to BBMVs, consistent with the results of ELISA and protein docking simulations. However, galectin-6 did not bind to Cadherin in far-western blotting or ELISA assay, though the protein docking simulations suggested their binding potential. These findings support the conclusion that galectin-6 may block Cry11Aa from binding to ALP1 and APN2 due to structural similarity, which might decrease the mosquitocidal toxicity of Cry11Aa.

中文翻译：

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埃及伊蚊 galectin-6 调节 Cry11Aa 毒性的作用

半乳糖凝集素是 β-半乳糖苷结合蛋白家族，昆虫半乳糖凝集素在免疫反应中发挥作用，也可能影响 Cry 毒素活性。在本研究中，我们旨在进一步了解埃及伊蚊 galectin-6 在调节 Cry11Aa 毒性中的功能和分子机制。A. aegypti galectin-6被克隆，重组galectin-6被表达和纯化。生物测定表明，galectin-6 可以降低 Cry11Aa 的毒性，从而保护 A. aegypti 幼虫。为了确定 galectin-6、Cry11Aa 和推定的毒素受体之间的相互作用，进行了 Octet Red 系统、蛋白质印迹、远蛋白质印迹和 ELISA 测定。Octet Red System 显示 galectin-6 与埃及蚊幼虫的 BBMV 结合，亲和力低于 Cry11Aa。蛋白质印迹和远蛋白质印迹分析表明，半乳糖凝集素 6 与 A. aegypti ALP1 和 APN2 以及 BBMV 结合，这与 ELISA 和蛋白质对接模拟的结果一致。然而，在远西方印迹或 ELISA 测定中，galectin-6 不与钙粘蛋白结合，尽管蛋白质对接模拟表明它们具有结合潜力。这些发现支持了以下结论：由于结构相似，galectin-6 可能会阻止 Cry11Aa 与 ALP1 和 APN2 结合，这可能会降低 Cry11Aa 的杀蚊毒性。