Divergent Polymer Superstructures from Protonated Poly(adenine) DNA and RNA

Area of Science:

• Biophysical Chemistry
• Nanotechnology
• Molecular Biology

Background:

• Poly(adenine) DNA and RNA strands protonate at low pH, forming self-associating duplexes.
• The nanoscopic morphology of these protonated structures remains unclear.
• Understanding these structures is crucial for applications in vaccine technologies, sensing, and dynamic biotechnology.

Purpose of the Study:

• To elucidate the unique hierarchical nanoscopic structures formed by protonated poly(adenine) DNA and RNA.
• To investigate the influence of ribose identity (DNA vs. RNA) and assembly conditions on structure formation.
• To understand the assembly pathways for developing programmable nanotechnologies.

Main Methods:

• Transition Electron Microscopy (TEM)
• Atomic Force Microscopy (AFM)
• Dynamic Light Scattering (DLS)
• Fluorescence Spectroscopy

Main Results:

• Protonated poly(adenine) DNA forms a discrete dimer (thermodynamic product) or a branched supramolecular polymer aggregating into micron-superstructures (kinetic product).
• Protonated poly(A) RNA polymerizes into micrometer-length, twisted fibers under identical conditions.
• Ribose identity and assembly conditions significantly dictate unique hierarchical structures.

Conclusions:

• Divergent hierarchical morphologies arise from subtle chemical differences between RNA and DNA.
• These findings amplify nanoscale behaviors and are critical for controlling assembly pathways.
• Control over these structures is essential for advancing programmable nanotechnologies.