An Artificial Insulin Receptor that Self-assembles and Works on a Gold Surface (Supporting Information)

A novel artificial insulin receptor was developed, that can self-assemble on a gold surface and alter its structure in response to insulin recognition via partial domains of the intrinsic insulin receptor. The candidates for the artificial insulin receptor were designed by fusing the αCT segment and L1CR domain of the insulin receptor with a gold-binding peptide to have self-assembling abilities on a gold surface. The proteins were termed 3GαL and αL3G, based on the order of these domains, and expressed in mammalian cells. A quartz crystal microbalance technique confirmed the ability of both proteins to self-assemble on the gold surface. Electrochemical impedance spectroscopy measurements using gold electrodes modified with these proteins revealed that 3GαL altered its structure in response to insulin recognition, even on a gold surface, confirming that it works as an artificial insulin receptor that self-assembles on a gold surface. We expect that 3GαL will contribute to the development of various biosensors that utilize gold surfaces as insulin-recognition elements.本研究开发了一种新型人工胰岛素受体（artificial insulin receptor），其可在金表面自组装，并能通过天然胰岛素受体的部分结构域响应胰岛素识别，进而改变自身构象。本研究通过将胰岛素受体的αCT段与L1CR结构域，与金结合肽（gold-binding peptide）融合，设计出人工胰岛素受体的候选蛋白，使其具备在金表面自组装的能力。根据这些结构域的拼接顺序，这两类蛋白被命名为3GαL与αL3G，并在哺乳动物细胞中完成了表达。石英晶体微天平（quartz crystal microbalance）技术证实，两种蛋白均具备在金表面自组装的能力。采用经该类蛋白修饰的金电极开展电化学阻抗谱（electrochemical impedance spectroscopy）检测，结果显示3GαL即便在金表面，仍可响应胰岛素识别而改变自身构象，证实其可作为可在金表面自组装的人工胰岛素受体发挥功能。本研究预期3GαL将有助于推动以金表面作为胰岛素识别元件的各类生物传感器的开发工作。