Conserved linear dynamics of single-molecule Brownian motion.

Area of Science:

• Biophysics
• Physical Chemistry
• Molecular Biology

Background:

• Macromolecular diffusion in fluids is typically modeled as a random process.
• Mean-squared displacement (MSD) analysis shows linear time dependence in the diffusive regime.
• Existing methods may overlook subtle non-random dynamics in molecular motion.

Purpose of the Study:

• To investigate non-random dynamics in macromolecular diffusion undetectable by standard MSD analysis.
• To quantify molecular motion relative to a lattice frame of reference.
• To reveal underlying sub-modes of motion in DNA diffusion.

Main Methods:

• Characterizing molecular motion relative to a latticed frame of reference.
• Utilizing lattice occupancy analysis.
• Analyzing deviations from expected random motion in the diffusive regime.

Main Results:

• Identified unexpected sub-modes of DNA motion deviating from random behavior.
• Demonstrated that these sub-modes interplay to maintain an overall linear diffusive appearance.
• Showed that non-random dynamics are detectable through relative motion analysis.

Conclusions:

• Apparently random macromolecular diffusion can be governed by non-random underlying dynamics.
• Lattice occupancy analysis provides a novel method to detect these hidden dynamics.
• This approach enhances the understanding of fundamental diffusion processes.