澳大利亚昆士兰科技大学Kirill Alexandrov团队报道了环状置换PQQ-葡萄糖脱氢酶作为超灵敏电化学生物传感器。相关研究成果发表在2021年10月12日出版的《德国应用化学》。

蛋白质生物传感器在研究和临床应用中扮演着越来越重要的角色。

该文中，研究人员提出了一种基于葡萄糖监测仪PQQ-葡萄糖脱氢酶（PQQ-GDH）主成分构建完全集成模块化的电化学生物传感器的方法。研究人员设计了变构调控的PQQ-GDH环状置换变体，在通过配体结合域（配体复合物）分子内支架形成新产生的N-和C-末端后，其酶活性发生了较大（>10倍）变化。所开发的生物传感器在比色和电化学分析中表现出对小分子和蛋白质的亚纳摩尔亲和力。例如，环孢菌素A的浓度可以在1毫升的未稀释血液中测量，其精确度与最先进的诊断技术相同，该技术使用的样本量是前者的50倍。

研究人员进一步使用该生物传感器构建高度多孔的金生物电极，能够在低至20pm的浓度下稳健地检测环孢素A的浓度，并在含有至少60%人类血清的样品中保留功能。以上实验表明，所开发的生物传感器平台是可推广的，并且可能适用于即时诊断。

附：英文原文

Title: Circular permutated PQQ-glucose dehydrogenase as an ultrasensitive electrochemical biosensor

Author: Kirill Alexandrov, Zhong Guo, Oleh Smutok, Wayne A. Johnston Wayne A. Johnston, Cagla Ergun Ayva, Patricia M Walden, Brett McWhinney, Jacobus Ungerer, Artem Melman, Evgeny Katz

Issue&Volume: 2021-10-12

Abstract: Protein biosensors play an increasingly important role as reporters for research and clinical applications. Here we present an approach for the construction of fully integrated but modular electrochemical biosensors based on the principal component of glucose monitors PQQ-glucose dehydrogenase (PQQ-GDH). We designed allosterically regulated circular permutated variants of PQQ-GDH that show large (>10 fold) changes in enzymatic activity following intramolecular scaffolding of the newly generated N- and C termini by ligand binding domain:ligand complexes. The developed biosensors demonstrated sub-nanomolar affinities for small molecules and proteins in colorimetric and electrochemical assays.  For instance, the concentration of Cyclosporine A could be measured in 1 ml of undiluted blood with the same accuracy as the leading diagnostic technique that uses 50 times more sample. We further used this biosensor to construct highly porous gold bioelectrodes capable of robustly detecting concentrations of Cyclosporine A as low as 20 pM and retained functionality in samples containing at least 60% human serum. These experiments suggest that the developed biosensor platform is generalizable and may be suitable for Point-of-Care diagnostics

DOI: 10.1002/anie.202109005

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202109005