Postsynthetic Modification of DNA Phosphodiester Backbone for Photocaged DNAzyme

Photocaged
(photoactivatable) biomolecules are powerful tools for
noninvasive control of biochemical activities by light irradiation.
DNAzymes (deoxyribozymes) are single-stranded oligonucleotides with
a broad range of enzymatic activities. In this work, to construct
photocaged DNAzymes, we developed a facile and mild postsynthetic
method to incorporate an interesting photolabile modification (thioether-enol
phosphate, phenol substituted, TEEP–OH) into readily
available phosphorothioate DNA. Upon light irradiation, TEEP–OH transformed into a native DNA phosphodiester, and accordingly the
DNAzymes with RNA-cleaving activities were turned “on”
from its inactive and caged form. Activation of the TEEP–OH-caged DNAzyme by light was also successful inside live cells.