초록 |
A specific DNA conjugated to an active protein is not only used to identify, manipulate and functionalize the protein but also, in itself, a programmable linker that can connect the protein to other molecules. However, maintaining a protein activity after the conjugation remains as a critical issue. In this work, we propose the use of guanine analogue for the aptamer-directed covalent conjugation of DNA to an unmodified protein. The guanine analogue, formed by nitrosation of guanine, is able to mediate activation-free crosslinking with nearby proteins. We invented a synthetic way to prepare this reactive base-containing aptamer and successfully confirmed that the newly synthesized aptamer forms a covalent linkage to the aimed location of protein with exceptionally high specificity. As a model, we demonstrate that a heparin-binding domain of thrombin is site-specifically conjugated with the selectively bound aptamer wherein the reactive base is included in a sequence-specific manner. |