Modified nucleic acid aptamers: development, characterization, and biological applications

Aptamer AS411 interacts with the KRAS promoter/hnRNP A1 complex and shows increased potency against drug-resistant lung cancer

“…Aptamers are short, single-stranded DNA or RNA ligands that can fold into unique three-dimensional structures to bind targets through spatial complementarities and intermolecular interactions. 1 Guanine-rich oligonucleotides (GRO) comprise many aptamers with the ability to form G4 structures. G4s are stabilized by the stacking of G-quartets, in which four guanines are assembled in a planar arrangement by Hoogsteen hydrogen bonding.…”

Chemoenzymatic Installation of Site-Specific Chemical Groups on DNA Enhances the Catalytic Activity

“…Several strategies have been explored to improve DNA functionalities through chemical modifications, including the binding affinities of DNA aptamers and catalytic activities of deoxyribozymes. − One common approach involves introducing protein-like functional groups to nucleobases, resulting in DNA aptamers with more extensive hydrophobic interactions, enlarged contact surface areas, and improved binding affinities . Similarly, chemical modifications have been employed to enhance the catalytic activities and biological stabilities of deoxyribozymes. − However, these modification strategies often entail the sophisticated preparation of chemically modified monomer building blocks, such as nucleoside triphosphates or phosphoramidites, followed by enzyme-mediated polymerization or solid-phase oligonucleotide synthesis, limiting the widespread accessibility of the approach.…”

Organometallic modification confers oligonucleotides new functionalities

“…40–48 Similar strategies have also met with considerable success in increasing the binding affinity and specificity of aptamers. 49–57 Chemical modification of ribozymes and DNAzymes 17,18 has largely focused on biostability but recently rationally designed changes based on high-resolution 3D structures have been shown to also improve the catalytic activity. 58 As long as the modifications are confined to the sugar moieties, such engineered nucleic acid catalysts still usually retain their reliance on metal ion cofactors.…”