Towards Improved Oligonucleotide Therapeutics Through Faster Target Binding Kinetics.

Area of Science:

• Molecular Biology
• Biochemistry
• Oligonucleotide Chemistry

Background:

• Oligonucleotides are crucial for gene silencing but require structural modifications to enhance binding affinity to target RNAs.
• Existing modifications, such as polyamino-groups, have shown limited success in improving oligonucleotide-RNA hybridization due to electrostatic repulsion.
• Developing effective modifications is essential for advancing oligonucleotide-based therapeutics and research tools.

Purpose of the Study:

• To investigate the efficacy of conjugating spermine to oligonucleotides via a triazole linker to enhance target RNA binding affinity.
• To determine the mechanism by which spermine conjugation impacts oligonucleotide hybridization kinetics.
• To explore the potential applications of spermine-modified oligonucleotides in gene expression inhibition and catalytic mechanisms.

Main Methods:

• Conjugation of spermine to uracil bases in oligonucleotides using a triazole linker.
• Assessment of binding affinity and hybridization kinetics using surface plasmon resonance (SPR) assays.
• Analysis of the structural implications of spermine incorporation into the RNA-duplex major groove.

Main Results:

• Spermine conjugation resulted in substantial increases in oligonucleotide binding affinity for complementary target RNAs.
• The enhanced binding was primarily attributed to significantly faster annealing rates (k_on).
• The spermine fragments were observed to fit within the major groove of the RNA-duplex.

Conclusions:

• Spermine conjugation represents a highly effective strategy for enhancing oligonucleotide-target RNA binding affinity.
• The improved hybridization kinetics suggest a role for spermine in facilitating oligonucleotide-RNA interactions, potentially mimicking natural polyamine functions.
• These findings hold promise for the development of more potent and efficient oligonucleotide-based gene silencing agents and catalytic systems.