Biosensing estrogenic endocrine disruptors in human blood and urine: A RAPID cell-free protein synthesis approach.

Many diseases and disorders are linked to exposure to endocrine disrupting chemicals (EDCs) that mimic the function of natural estrogen hormones. Here we present a Rapid Adaptable Portable In-vitro Detection biosensor platform (RAPID) for detecting chemicals that interact with the human estrogen receptor ß (hERß). This biosensor consists of an allosteric fusion protein, which is expressed using cell-free protein synthesis technology and is directly assayed by a colorimetric response. The resultant biosensor successfully detected known EDCs of hERß (BPA, E2, and DPN) at similar or better detection range than an analogous cell-based biosensor, but in a fraction of time. We also engineered cell-free protein synthesis reactions with RNAse inhibitors to increase production yields in the presence of human blood and urine. The RAPID biosensor successfully detects EDCs in these human samples in the presence of RNAse inhibitors. Engineered cell-free protein synthesis facilitates the use of protein biosensors in complex sample matrices without cumbersome protein purification.

Cell-Free Protein Synthesis Approach to Biosensing hTRß-Specific Endocrine Disruptors.

Here we introduce a Rapid Adaptable Portable In vitro Detection biosensor platform (RAPID) for detecting ligands that interact with nuclear hormone receptors (NHRs). The RAPID platform can be adapted for field use, allowing rapid evaluation of endocrine disrupting chemicals (EDCs) presence or absence in environmental samples, and can also be applied for drug screening. The biosensor is based on an engineered, allosterically activated fusion protein, which contains the ligand binding domain from a target NHR (human thyroid receptor ß in this work). In vitro expression of this protein using cell-free protein synthesis (CFPS) technology in the presence of an EDC leads to activation of a reporter enzyme, reported through a straightforward colorimetric assay output. In this work, we demonstrate the potential of this biosensor platform to be used in a portable "just-add-sample" format for near real-time detection. We also demonstrate the robust nature of the cell-free protein synthesis component in the presence of a variety of environmental and human samples, including sewage, blood, and urine. The presented RAPID biosensor platform is significantly faster and less labor intensive than commonly available technologies, making it a promising tool for detecting environmental EDC contamination and screening potential NHR-targeted pharmaceuticals.