小柯机器人

近日，美国华盛顿大学David Baker、Byung-Ha Oh等研究人员合作实现模块化蛋白生物传感器的从头设计。相关论文于2021年1月27日在线发表在《自然》杂志上。

研究人员表明，可以通过从头设计的蛋白质开关反转信息流来创建非常通用的蛋白质生物传感器，其中肽键的结合会触发所需的生物输出。这种设计的传感器是模块化的分子器件，具有封闭的暗态和开放的发光态；分析物的结合可驱动开关从关闭状态切换到打开状态。由于该传感器仅基于分析物与传感器激活的热力学耦合，因此仅需要一个靶标结合域，从而简化了传感器设计并能够直接在溶液中读值。

研究人员通过创建生物传感器来证明了该平台的模块化，该生物传感器几乎没有进行优化，可以灵敏地检测抗凋亡蛋白Bcl-2、IgG1 Fc结构域、Her2受体和肉毒杆菌神经毒素B，以及心脏肌钙蛋白I和一种抗乙型肝炎病毒（HBV）抗体，并可达到检测这些分子临床相关浓度所需的亚纳摩尔级敏感性。

鉴于当前需要用于跟踪COVID-19的诊断工具，研究人员使用该方法设计了针对SARS-CoV-2蛋白表位的抗体和SARS-CoV-2突刺蛋白的受体结合域（RBD）的传感器。后者结合了从头设计的RBD结合分子，其检测极限为15 pM，背景信号超过50倍。平台的模块化和灵敏性可快速构建适用于各种分析物的传感器，并强调了从头进行蛋白质设计的能力，这能够用于创建具有新功能且有实用性的多状态蛋白质系统。 

据了解，天然存在的蛋白质开关已被重新用于开发用于细胞和临床应用的新型生物传感器和报告分子，但此类开关的数量有限，并且由于每个开关的不同，对其进行工程设计通常具有挑战性。

附：英文原文

Title: De novo design of modular and tunable protein biosensors

Author: Alfredo Quijano-Rubio, Hsien-Wei Yeh, Jooyoung Park, Hansol Lee, Robert A. Langan, Scott E. Boyken, Marc J. Lajoie, Longxing Cao, Cameron M. Chow, Marcos C. Miranda, Jimin Wi, Hyo Jeong Hong, Lance Stewart, Byung-Ha Oh, David Baker

Issue&Volume: 2021-01-27

Abstract: Naturally occurring protein switches have been repurposed for developing novel biosensors and reporters for cellular and clinical applications1, but the number of such switches is limited, and engineering them is often challenging as each is different. Here, we show that a very general class of protein-based biosensors can be created by inverting the flow of information through de novo designed protein switches in which binding of a peptide key triggers biological outputs of interest2. The designed sensors are modular molecular devices with a closed dark state and an open luminescent state; binding of the analyte of interest drives switching from the closed to the open state. Because the sensor is based purely on thermodynamic coupling of analyte binding to sensor activation, only one target binding domain is required, which simplifies sensor design and allows direct readout in solution. We demonstrate the modularity of this platform by creating biosensors that, with little optimization, sensitively detect the anti-apoptosis protein Bcl-2, the IgG1 Fc domain, the Her2 receptor, and Botulinum neurotoxin B, as well as biosensors for cardiac Troponin I and an anti-Hepatitis B virus (HBV) antibody that achieve the sub-nanomolar sensitivity necessary to detect clinically relevant concentrations of these molecules. Given the current need for diagnostic tools for tracking COVID-193, we used the approach to design sensors of antibodies against SARS-CoV-2 protein epitopes and of the receptor-binding domain (RBD) of the SARS-CoV-2 Spike protein. The latter, which incorporates a de novo designed RBD binder4, has a limit of detection of 15 pM and a signal over background of over 50-fold. The modularity and sensitivity of the platform should enable the rapid construction of sensors for a wide range of analytes and highlights the power of de novo protein design to create multi-state protein systems with new and useful functions.

DOI: 10.1038/s41586-021-03258-z

Source: https://www.nature.com/articles/s41586-021-03258-z

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html