Heart-type fatty acid-binding protein in the early diagnosis of acute myocardial infarction: a systematic review and meta-analysis

Abstract

<h3>Abstract</h3> In synthetic biology, biosensors are routinely coupled to a gene expression cascade for detecting small molecules and physical signals. We posit that an alternative direct protein (DiPro) biosensor mechanism, could provide a new opportunity for rapid detection of specific chemicals. Herein, we reveal a fluorescent curcumin DiPro biosensor, based on the <i>Escherichia</i> coli double bond reductase (<i>Ec</i>CurA) as a detection system. We characterise the <i>Ec</i>CurA DiPro biosensor and propose enhanced curcumin fluorescence is generated through π-π stacking between protein and ligand. Using a cell-free synthetic biology approach, we use the <i>Ec</i>CurA DiPro biosensor to fine tune 10 reaction parameters (cofactor, substrate, and enzyme levels) for cell-free biosynthesis, assisted through acoustic liquid handling robotics. Overall, we increase <i>Ec</i>CurA-curcumin fluorescence by 80-fold. We speculate that a generic DiPro biosensor fluorescence mechanism can be further exploited for a wider range of chemicals that share intrinsic fluorescence and have a suitable binding protein.