Accelerating Riboswitch Engineering for the Development of Human Performance Biosensors

The Air Force Research Laboratory (AFRL) is interested in different sensor platforms for the detection of Airman Performance biomarkers, such as serotonin, dopamine, and cortisol. One sensing modality of interest includes riboswitches, which are RNA regulatory elements typically found in the 5’ untranslated region of bacterial operons. The use of riboswitches as sensing elements for synthetic biology applications is appealing, especially as techniques to engineer synthetic aptamers have advanced. However, efforts to rationally design riboswitches have been limited by an incomplete understanding of the properties that link the structure of the aptamer domain to the structure of the expression regulatory domain. Most chimeric designs require considerable optimization of several key sequence parameters before producing a functional switch. As part of a joint effort organized by DARPA, Strateos and AFRL are collaborating to iteratively develop novel riboswitches that recognize the biomarker serotonin. AFRL leverages the Strateos automated robotic cloud lab’s Design-Build-Test-Learn (DBTL) platform to iteratively screen RNA sequences using a modular pbuE expression system and an E. coli extract-based cell-free protein expression assays. This presentation will highlight how the automated cloud lab accelerated riboswitch engineering for the development of novel biosensors.