Creating a Thermostable β-Glucuronidase Switch for Homogeneous Immunoassay by Disruption of Conserved Salt Bridges at Diagonal Interfaces.Escherichia coli β-glucuronidase (GUS) has been used as a reporter enzyme in molecular biology and engineered as an enzyme switch for the development of homogeneous biosensors.  In this study, we developed a thermostable GUS enzyme switch based on the thermostable GUS mutant TR3337 by disrupting a conserved salt bridge (H514-E523) between the diagonal subunits of its homotetramer.  Up to 1.8-fold of signal-to-background ratio was confirmed when measured at up to 45 °C, thereby highlighting the DLW mutant as a versatile tool for developing thermostable immunosensors for in vitro and in cellulo applications.
THERM