A d -2-hydroxyglutarate biosensor based on specific transcriptional regulator DhdR

d -2-Hydroxyglutarate ( d -2-HG) is a metabolite involved in many physiological metabolic processes. When d -2-HG is aberrantly accumulated due to mutations in isocitrate dehydrogenase or d -2-HG dehydrogenase, it functions in a pro-oncogenic manner and is thus considered a therapeutic target and biomarker in many cancers. In this study, DhdR from Achromobacter denitrificans NBRC 15125 is identified as an allosteric transcriptional factor that negatively regulates d -2-HG dehydrogenase expression and responds to the presence of d -2-HG. Based on the allosteric effect of DhdR, a d -2-HG biosensor is developed by combining DhdR with amplified luminescent proximity homogeneous assay (AlphaScreen) technology. The biosensor is able to detect d -2-HG in serum, urine, and cell culture medium with high specificity and sensitivity. Additionally, this biosensor is used to identify the role of d -2-HG metabolism in lipopolysaccharide biosynthesis of Pseudomonas aeruginosa , demonstrating its broad usages.