| Synthetic oligonucleotides coupled with photolabile caging groups have been developed to regulate a variety of biological processes in a spatial and temporal fashion. A UV-cleavable caging group was installed on deoxyadenosine and two morpholino oligonucleotide (MO) monomers of which the morpholino core synthesis was also investigated. The synthesis of a two-photon caging group was optimized and two chromophores with > 400 nm absorption maximum were applied to cage thymidine. These caged monomers can serve as light-triggers of oligonucleotide function upon incorporation. Two phosphine-labile azido thymidine derivatives were synthesized as orthogonal small molecule-triggers to the above light-triggers.;Additionally, two coumarin linkers were synthesized, which can cyclize a linear MO so as to inactivate MO activity until > 400 nm light irradiation. These two linkers have been applied to the wavelength-selective regulation of zebrafish embryo development. An azide linker was also synthesized to control MOs using phosphines, as well as a UV-cleavable phosphoramidite to regulate DNA oligonucleotide activities.;On the regulation of proteins, a two-photon caged lysine, four azido lysines and an azido tyrosine were synthesized to control protein function with either light or small molecules. The phosphine-induced cleavage of the azido groups were investigated on a coumarin reporter. A fluorescent lysine and an isotope labeled lysine were also synthesized as additional biophysical probes to label protein. These unnatural amino acids have been or will be incorporated into proteins through exogenous tRNA-aaRSs pairs. |
