Abstract
Proteins detection is very important in biology and medicine because abnormal protein concentrations in cells are indicative of many diseases. Traditional protein detection methods such as western blot and enzyme-linked immunosorbent assay (ELISA) which uses a covalently labeled enzyme-antibody conjugate to carry out specific analyte detection and signal amplification, are laborious and time consuming. Currently, development of a rapid, selective and sensitive protein detection method remains a challenging task. Herein, I introduce a new type of protein-specific fluorescent turn-on probes, where a small molecule ligand is conjugated to an environment-sensitive fluorophore, for the selective detection of both non-enzymatic proteins and enzymatic proteins. The fluorescent turn-on mechanism is based on the binding of the ligand to a hydrophobic ligand binding domain of the target protein whereby the close proximity to the hydrophobic environment can influence the environment-sensitive fluorophore to exhibit stronger fluorescence. With this design, we have successfully constructed an environment-sensitive fluorescent probe for specific detection of dihydropteroate synthase (DHPS) as well as sulfonamide detection. We also applied the similar probe design to Biotin-Avidin System (BAS) in which biotin was used as the ligand for the interaction with avidin. We believe that this design of fluorescence probes can have many future applications, such as immuno-precipitation and biometric.