Precisely Defined Aptamer-b-Poly(phosphodiester) Conjugates Prepared by Phosphoramidite Polymer Chemistry

Area of Science:

• Bioconjugation Chemistry
• Polymer Science
• Molecular Biology

Background:

• DNA aptamers offer specific molecular recognition capabilities.
• Synthetic polymers can impart unique properties to biomolecules.
• Combining aptamers and polymers requires precise and controlled conjugation methods.

Purpose of the Study:

• To synthesize uniform DNA aptamer-polymer conjugates using automated phosphoramidite chemistry.
• To demonstrate the versatility of this method with natural and non-natural monomers.
• To characterize the resulting bioconjugates and confirm aptamer structural integrity.

Main Methods:

• Automated phosphoramidite chemistry for multistep polymer growth.
• Synthesis of six distinct aptamer-polymer conjugates using various monomers.
• Characterization via ion-exchange HPLC, circular dichroism spectroscopy, and electrospray mass spectrometry.

Main Results:

• Successful synthesis of uniform aptamer-polymer conjugates with controlled chain length and monomer sequence.
• Confirmation of precise molecular structure through multiple analytical techniques.
• Demonstration that polymer conjugation does not affect DNA aptamer folding.

Conclusions:

• A straightforward and versatile method for creating uniform DNA aptamer-polymer conjugates has been established.
• This technique enables covalent attachment of homopolymers and copolymers to DNA aptamers.
• The method preserves the biofunctionality of the attached aptamers.