Department of Biomedical Engineering, McCormick School of Engineering and Applied Science, Northwestern University, Evanston, IL, USA.
Center for Synthetic Biology, Northwestern University, Evanston, IL, USA.
Sci Adv. 2023 Jan 4;9(1):eadd6605. doi: 10.1126/sciadv.add6605.
Cell-free systems have enabled the development of genetically encoded biosensors to detect a range of environmental and biological targets. Encapsulation of these systems in synthetic membranes to form artificial cells can reintroduce features of the cellular membrane, including molecular containment and selective permeability, to modulate cell-free sensing capabilities. Here, we demonstrate robust and tunable performance of a transcriptionally regulated, cell-free riboswitch encapsulated in lipid membranes, allowing the detection of fluoride, an environmentally important molecule. Sensor response can be tuned by varying membrane composition, and encapsulation protects from sensor degradation, facilitating detection in real-world samples. These sensors can detect fluoride using two types of genetically encoded outputs, enabling detection of fluoride at the Environmental Protection Agency maximum contaminant level of 0.2 millimolars. This work demonstrates the capacity of bilayer membranes to confer tunable permeability to encapsulated, genetically encoded sensors and establishes the feasibility of artificial cell platforms to detect environmentally relevant small molecules.
无细胞系统使能够开发遗传编码的生物传感器来检测一系列环境和生物靶标。将这些系统封装在合成膜中形成人工细胞，可以重新引入细胞膜的特征，包括分子容纳和选择性渗透性，以调节无细胞传感能力。在这里，我们展示了转录调控的无细胞核糖体开关在脂质膜中的封装的稳健和可调的性能，允许检测环境重要分子氟化物。通过改变膜组成可以调整传感器的响应，并且封装可以防止传感器降解，从而促进在实际样品中的检测。这些传感器可以使用两种类型的遗传编码输出来检测氟化物，从而能够检测到环境保护署规定的 0.2 毫摩尔的最大污染物氟化物。这项工作证明了双层膜赋予封装的遗传编码传感器可调渗透性的能力，并确立了人工细胞平台检测环境相关小分子的可行性。
