The COVID-19 pandemic caused by SARS-CoV-2 has applied significant pressure on overtaxed healthcare around the world, underscoring the urgent need for rapid diagnosis and treatment. We have developed a bacterial strategy for the expression and purification of a SARS-CoV-2 spike protein receptor binding domain (RBD) that includes the SD1 domain. Bacterial cytoplasm is a reductive environment, which is problematic when the recombinant protein of interest requires complicated folding and/or processing. The use of the CyDisCo system (cytoplasmic disulfide bond formation in E. coli) bypasses this issue by pre-expressing a sulfhydryl oxidase and a disulfide isomerase, allowing the recombinant protein to be correctly folded with disulfide bonds for protein integrity and functionality. We show that it is possible to quickly and inexpensively produce an active RBD in bacteria that is capable of recognizing and binding to the ACE2 (angiotensin-converting enzyme) receptor as well as antibodies in COVID-19 patient sera.

中文翻译：

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CyDisCo 生产功能性重组 SARS-CoV-2 刺突受体结合域

由 SARS-CoV-2 引起的 COVID-19 大流行给全世界负担过重的医疗保健带来了巨大压力，凸显了对快速诊断和治疗的迫切需求。我们开发了一种细菌策略，用于表达和纯化包含 SD1 结构域的 SARS-CoV-2 刺突蛋白受体结合域 (RBD)。细菌细胞质是还原环境，当感兴趣的重组蛋白需要复杂的折叠和/或加工时，这是有问题的。使用 CyDisCo 系统（大肠杆菌中细胞质二硫键的形成）) 通过预表达一个巯基氧化酶和一个二硫键异构酶绕过了这个问题，允许重组蛋白正确地折叠二硫键以保证蛋白质的完整性和功能。我们表明，可以在细菌中快速且廉价地产生活性 RBD，该活性 RBD 能够识别并结合 ACE2（血管紧张素转换酶）受体以及 COVID-19 患者血清中的抗体。