Abstract: The present disclosure provides nucleic acid-based nanoswitch catenanes and methods of use. A nanoswitch catenane may include a single-stranded nucleic acid comprising a first and second terminal domain linked to each other to form a host ring by one of a first, second or third switchable bridges, wherein the first switchable bridge is formed in the presence of a reaction agent through the reaction of two cognate functional groups, each linked to a terminal domain of the single-stranded nucleic acid, wherein the second switchable bridge is formed in the presence of a biomolecule of interest through binding of the bio-molecule of interest to two cognate antibodies, each linked to a terminal domain of the single stranded nucleic acid, and wherein the third switchable bridge is a link between two cognate functional groups that breaks in the presence of a dissociation agent. A nanoswitch catenane may also include a circular nucleic acid guest ring catenated with the host ring.

Abstract: HDAC inhibitors of the general formula (I) and (II) and pharmaceutically acceptable salts thereof, as described herein, are useful as inhibitors of histone deacetylases or other deacetylases, and thus are useful for the treatment of various diseases and disorders associated with acetylase/deacetylase activity as described herein (e.g., cancer). In certain embodiments, the compounds of the invention selectively target either a class or isoform of the HDAC family. Another aspect of the invention provides an assay for determining the inhibitory effect of a test compound on an HDAC protein comprising: incubating the HDAC protein with a substrate of general formula (IIIc) in the presence of a test compound; and determining the activity of the HDAC protein.