Patent ID: 8257918

Claim:
A method of controlling the activity of a biologically active compound, comprising: a) providing a hairpin-forming oligonucleotide capable of existing in either a hairpin configuration having a single-stranded loop and a double-stranded stem, or an open configuration lacking the double-stranded stem; b) physically associating an effector moiety with the oligonucleotide, said effector moiety having a biological activity; c) physically associating a regulating moiety with the oligonucleotide, said regulating moiety controlling the biological activity of the effector moiety when the regulating and effector moieties interact; and d) changing from one configuration to the other; wherein the regulating moiety interacts with the effector moiety when the oligonucleotide is in the hairpin configuration, and the regulating and effector moieties fail to interact when the oligonucleotide is in the open configuration, and wherein the biological activity comprises sterically blocking a target molecule.