Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA.
Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, MD, USA.
Biotechnol Prog. 2022 Nov;38(6):e3297. doi: 10.1002/btpr.3297. Epub 2022 Aug 29.
β-galactosidase (β-gal) is one of the most prevalent markers of gene expression. Its activity can be monitored via optical and fluorescence microscopy, electrochemistry, and many other ways after slight modification using protein engineering. Here, we have constructed a chimeric version that incorporates a streptococcal protein G domain at the N-terminus of β-gal that binds immunoglobins, namely IgG. This protein G: β-galactosidase fusion enables β-gal-based spectrophotometric and electrochemical measurements of IgG. Moreover, our results show linearity over an industrially relevant range. We demonstrate applicability with rapid spectroelectrochemical detection of IgG in several formats including using an electrochemical sensing interface that is rapidly assembled directly onto electrodes for incorporation into biohybrid devices. The fusion protein enables sensitive, linear, and rapid responses, and in our case, makes IgG measurements quite robust and simple, expanding the molecular diagnostics toolkit for biological measurement.
β-半乳糖苷酶（β-gal）是基因表达最普遍的标志物之一。经过蛋白质工程的轻微修饰，其活性可以通过光学和荧光显微镜、电化学和许多其他方法进行监测。在这里，我们构建了一种嵌合版本，在β-gal 的 N 端融合了链球菌蛋白 G 结构域，该结构域可以结合免疫球蛋白，即 IgG。这种蛋白 G:β-半乳糖苷酶融合蛋白可以实现基于β-gal 的 IgG 的分光光度法和电化学测量。此外，我们的结果表明在工业相关范围内具有线性关系。我们通过几种格式的快速光谱电化学检测 IgG 证明了其适用性，包括使用电化学传感界面，该界面可以快速组装到电极上，以便纳入生物混合设备。融合蛋白可以实现灵敏、线性和快速的响应，在我们的情况下，使 IgG 测量变得相当稳健和简单，为生物测量扩展了分子诊断工具包。
