RESUMO
The thrombin binding aptamer (TBA) is a promising nucleic acid-based anticoagulant. We studied the effects of chemical modifications, such as dendrimer Trebler and NHS carboxy group, on TBA with respect to its structures and thrombin binding affinity. The two dendrimer modifications were incorporated into the TBA at the 5' end and the NHS carboxy group was added into the thymine residues in the thrombin binding site of the TBA G-quadruplex (at T4, T13 and both T4/T13) using solid phase oligonucleotide synthesis. Circular dichroism (CD) spectroscopy confirmed that all of these modified TBA variants fold into a stable G-quadruplex. The binding affinity of TBA variants with thrombin was measured by surface plasmon resonance (SPR). The binding patterns and equilibrium dissociation constants (KD) of the modified TBAs are very similar to that of the native TBA. Molecular dynamics simulations studies indicate that the additional interactions or stability enhancement introduced by the modifications are minimized either by the disruption of TBA-thrombin interactions or destabilization elsewhere in the aptamer, providing a rational explanation for our experimental data. Overall, this study identifies potential positions on the TBA that can be modified without adversely affecting its structure and thrombin binding preference, which could be useful in the design and development of more functional TBA analogues.
Assuntos
Anticoagulantes/síntese química , Aptâmeros de Nucleotídeos/síntese química , Quadruplex G , Oligonucleotídeos/síntese química , Trombina/química , Anticoagulantes/metabolismo , Anticoagulantes/farmacologia , Aptâmeros de Nucleotídeos/metabolismo , Aptâmeros de Nucleotídeos/farmacologia , Sequência de Bases , Sítios de Ligação , Coagulação Sanguínea/efeitos dos fármacos , Dendrímeros/química , Humanos , Cinética , Simulação de Dinâmica Molecular , Conformação de Ácido Nucleico , Oligonucleotídeos/metabolismo , Ligação Proteica , Termodinâmica , Trombina/antagonistas & inibidores , Trombina/metabolismoRESUMO
Correction for 'Click and photo-release dual-functional nucleic acid nanostructures' by Vibhav A. Valsangkar et al., Chem. Commun., 2019, DOI: 10.1039/c9cc03806j.
RESUMO
We functionalize nucleic acid nanostructures with click chemistry (for attachment of cargos) and a photocleavable linker (for release). We demonstrate cargo attachment using a fluorescein dye and release using UV trigger from an RNA three-way junction, a DNA star motif and a DNA tetrahedron. Such multifunctional nucleic acid nanostructures have potential in targeted drug delivery.
