Construction Of Biochemical Sensors Based On Enzyme-catalyzed Reaction

Enzymes are important macromolecules in organism,which play an essential role in various biological and physiological events.Abnormal expressions of enzymes are always associated with various kinds of diseases,especially,cancer.Thus,developing an ultra-sensitive and high selective method for the detection of enzymes will be of great significance for diagnosis,treatment and management of cancer.Fluorescent probes are an effective analytical method which has attracted extensive attention for its high sensitivity,good selectivity,simple operation,low biological invasion and high temporal spatial resolution etc..In recent years,fluorescent probes have been widely used in analytical methods and bioimaging,which have made great contributions to related research area.In this paper,based on these important roles played by enzymes,and the great convenience of fluorescent probes in bioimaging,we attempted to design and synthesize several kind of biosensors,so as to realize the real-time monitoring of leucine aminopeptidase(LAP)and aryl sulfatase(ARS)in living system.(1)We designed and synthesized a theranostic prodrug(CPT-p-Leu)activated by a Leucine aminopeptidase(LAP).In the presence of LAP,the amide bond in CPT-p-Leu will be cleavaged and followed by an intramolecular 1,6-elimination to release active anti-cancer drug,CPT,and restore the fluorescence of CPT at the same time.In this way,the prodrug molecule CPT-p-Leu achieves the purpose of specifically monitoring LAP activity and effectively killing related cancer cells to achieve integration of diagnosis and treatment.We hope this work can provide some reference for related cancer diagnosis,treatment and management.(2)We constructed two biosensors,DCM-S and Coumarin-S,based on DCM-OH and coumarin for specific recognition of arylsulfatase(ARS).In the presence of ARS,the sulfate bond in these two biosensors will be specifically cleavaged by ARS to restore the fluorescence of these two fluorophores.In this way,DCM-S and Coumarin-S realized the chemoselective detection of ARS.(3)We designed and synthesized a novel biosensors(CHMC-N-Leu)for monitoring leucine aminopeptidase(LAP)in biological system.In our strategy,LAP selectively catalyzes the hydrolysis of the amide bond in CHMC-N-Leu,and the released amino group will further attack the ester bond in this molecule,and the fluorophore,CHMC,will be released,accompanying with a strong fluorescence enhancement.Base on this strategy,CHMC-N-Leu may realize the chemoselective detection of LAP.