Coiled-coil (CC) dimer-forming peptides are attractive designable modules for mediating protein association. Highly stable CCs are desired for biological activity regulation and assay. Here, we report the design and versatile applications of orthogonal CC dimer-forming peptides with a dissociation constant in the low nanomolar range. In vitro stability and specificity was confirmed in mammalian cells by enzyme reconstitution, transcriptional activation using a combination of DNA-binding and a transcriptional activation domain, and cellular-enzyme-activity regulation based on externally-added peptides. In addition to cellular regulation, coiled-coil-mediated reporter reconstitution was used for the detection of cell fusion mediated by the interaction between the spike protein of pandemic SARS-CoV2 and the ACE2 receptor. This assay can be used to investigate the mechanism and screen inhibition of viral spike protein-mediated fusion under the biosafety level 1conditions.

中文翻译：

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线圈螺旋异二聚体，具有更高的稳定性，可用于细胞调节和传感SARS-CoV-2穗蛋白介导的细胞融合

螺旋线圈（CC）形成二聚体是介导蛋白质缔合的有吸引力的可设计模块。高度稳定的CC对于生物学活性的调节和测定是需要的。在这里，我们报道了在低纳摩尔范围内具有解离常数的正交CC二聚体形成肽的设计和广泛应用。通过酶重建，结合DNA结合和转录激活域的转录激活以及基于外部添加肽的细胞酶活性调节，在哺乳动物细胞中证实了体外稳定性和特异性。除了细胞调节外，还使用卷曲螺旋介导的报道基因重建来检测由大流行性SARS-CoV2的突突蛋白和ACE2受体之间的相互作用介导的细胞融合。