Journal: bioRxiv
Article Title: In vitro transcription-based biosensing of glycolate for prototyping of a complex enzyme cascade
doi: 10.1101/2024.04.26.591264
Figure Lengend Snippet: Characterization of a glycolate-responsive in vitro transcription-based biosensor module. A: The ROSALIND system is based on the controlled expression of the 3WJdB RNA aptamer and the correlating fluorescence signal of the 3WJdB :DFHBI-1T complex. Expression is regulated by a transcriptional repressor that binds to an operator sequence downstream of a T7 promoter. The repression is lifted in a dose-responsive manner by binding of an effector molecule to the aTF. This system allows faster and cheaper sample measurement in microtiter plates than analysis by LC-MS, but its precision is yet unknown. Time estimates refer to glycolate quantification. B, C: The dose-response curve of the GlcR sensor module to 100 nM to 100 mM glycolate (16 h time point) shows an operational range from 10 µM to 20 mM glycolate with an excellent correlation between 16 µM and 8 mM glycolate and a 10-fold dynamic range. Note that IVT biosensing reactions are highly time-sensitive (Supplementary Figure 5). D: Promiscuity assay of GlcR shows a low-level dose response to DL-lactate and DL-glycerate. Raw fluorescence data are standardized to MEF (µM fluorescein). Data are the mean of n =3 technical replicates ± s.d. IVT output without effector molecule and without MGlcR is shown as horizontal dotted lines.
Article Snippet: The reactions were mixed by pipetting and 3x 20 μL were immediately transferred into a 384-well, black, optically clear, flat-bottom, non-binding microtiter plate (Greiner Bio-One, Kremsmünster, Austria; catalog no.: 781906).
Techniques: In Vitro, Expressing, Fluorescence, Sequencing, Binding Assay, Liquid Chromatography with Mass Spectroscopy