The Potential Application Of Tetrazole-based Probes In Phenotypic Screening,Affinity-based Proteome Profiling,and Sensitive Detection Of A Cancer Biomarker

Phenotypic screening has been a powerful approach in drug discovery.Many bioactivie molecules were discovered through this method.However it's hindered by difficulties in identifying the cellular targets.To address this issue,we have combined phenotypic screening with affinity-based proteome profiling(ABPP)to map and functionally characterize the targets of screening hits.In drug discovery,activity-based protein profiling has been widely applied in uncovering new drug targets related to diseases,identifying cellular on/off targets of drugs.The probes covalently modify target proteins and subsequently facilitate isolation and identification of target proteins.Due to the non-covalent interactions for most bioactive molecules with their targets,a photo-crosslinker is required to form a covalent bond between the probe and bound protein upon UV-irradiation.The previously reported photo-crosslinkers are suffering from various disadvantages.For example,benzophenone requires long UV-irradiation time,the crosslinking yield of aryl azide is less than 30%.Recently,we found that 2,5-diaryltetrazole can behave as a highly efficient photo-crosslinker which can be photolysised in short UV-irradiation time and afford high crosslinking yield.In this project,we discovered the efficiency of tetrazole-based photo-crosslinkers and found that 2,5-diphenyltetrazole can serve as an efficient photo-crosslinker with superior protein crosslinking ability.We further synthesised a series of fully functionalized tetrazole-based probes for phenotypic screening.Several tetrazole-based probes were capable of displaying remarkable bioactivity towards several cancer cell lines.Then,we identified ANXA2,FLAD1 and NOS2 as the potential cellular targets of these bioactive molecules that inhibit cancer cell proliferation by activity-based protein profiling.We further demonstrated that a tetrazole-based probe can label and imagine endogenous Annexin A2(a cancer biomarker)in various cancer cell lines with high selectivity.In conclusion,these tetrazole-based probes provide opportunities for potential cancer diagnosis and therapy.