Ming Ke, Xing Banbin, Ren Xinyi, Hu Yang, Wei Lin, Wang Zhizheng, Mei Meng, Weng Jun, Wei Zigong
State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China; Hubei Jiangxia Laboratory, Wuhan, Hubei, PR China.
State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, PR China.
Int J Biol Macromol. 2024 Sep;276(Pt 1):133834. doi: 10.1016/j.ijbiomac.2024.133834. Epub 2024 Jul 11.
IL-2 regulates the immune response by interacting with different IL-2 receptor (IL-2R) subunits. High dose of IL-2 binds to IL-2Rβγ heterodimer, which induce various side effects while activating immune function. Disrupting IL-2 and IL-2R interactions can block IL-2 mediated immune response. Here, we used a computational approach to de novo design mini-binder proteins against IL-2R β chain (IL-2Rβ) to block IL-2 signaling. The hydrophobic region where IL-2 binds to IL-2Rβ was selected and the promising binding mode was broadly explored. Three mini-binders with amino acid numbers ranging from 55 to 65 were obtained and binder 1 showed the best effects in inhibiting CTLL-2 cells proliferation and STAT5 phosphorylation. Molecular dynamics simulation showed that the binding of binder 1 to IL-2Rβ was stable; the free energy of binder1/IL-2Rβ complex was lower, indicating that the affinity of binder 1 to IL-2Rβ was higher than that of IL-2. Free energy decomposition suggested that the ARG35 and ARG131 of IL-2Rβ might be the key to improve the affinity of binder. Our efforts provided new insights in developing of IL-2R blocker, offering a potential strategy for ameliorating the side effects of IL-2 treatment.
白细胞介素-2（IL-2）通过与不同的白细胞介素-2受体（IL-2R）亚基相互作用来调节免疫反应。高剂量的IL-2与IL-2Rβγ异二聚体结合，在激活免疫功能的同时会引发各种副作用。破坏IL-2与IL-2R的相互作用可阻断IL-2介导的免疫反应。在此，我们采用一种计算方法从头设计针对IL-2受体β链（IL-2Rβ）的微型结合蛋白，以阻断IL-2信号传导。我们选择了IL-2与IL-2Rβ结合的疏水区域，并广泛探索了有前景的结合模式。获得了三种氨基酸数量在55至65之间的微型结合蛋白，其中结合蛋白1在抑制CTLL-2细胞增殖和信号转导及转录激活因子5（STAT5）磷酸化方面表现出最佳效果。分子动力学模拟表明，结合蛋白1与IL-2Rβ的结合是稳定的；结合蛋白1/IL-2Rβ复合物的自由能较低，表明结合蛋白1与IL-2Rβ的亲和力高于IL-2。自由能分解表明，IL-2Rβ的精氨酸35（ARG35）和精氨酸131（ARG131）可能是提高结合蛋白亲和力的关键。我们的研究为开发IL-2R阻断剂提供了新的见解，为改善IL-2治疗的副作用提供了一种潜在策略。
