Anomalous reaction-diffusion as a model of nonexponential DNA escape kinetics

Area of Science:

• Biophysics
• Physical Chemistry
• Computational Biology

Background:

• Experimental data on DNA escape from alpha-hemolysin nanopores exhibit nonexponential survival probability decays.
• Previous interpretations attributed these decays to a distribution of trapping potentials.
• The Becquerel function was used to fit the experimental survival probability data.

Purpose of the Study:

• To rationalize experimental data on DNA escape kinetics from nanopores using a novel theoretical model.
• To investigate the role of anomalous diffusion in DNA trapping and escape dynamics.
• To compare the predictive power of the proposed model against existing explanations.

Main Methods:

• Developed a theoretical model based on anomalous diffusion of a particle in a harmonic well with a delta function sink.
• Applied the model to analyze DNA escape kinetics data from alpha-hemolysin nanopores.
• Utilized Mittag-Leffler and generalized Mittag-Leffler functions to describe survival probability at different time scales.

Main Results:

• The proposed anomalous diffusion model successfully rationalizes the experimental data on DNA escape kinetics.
• The model predicts survival probability using Mittag-Leffler functions at short times and generalized Mittag-Leffler functions at long times.
• The model provides a better fit to the experimental data compared to the previously used Becquerel function.

Conclusions:

• Anomalous diffusion offers a plausible explanation for the observed nonexponential decays in DNA escape kinetics.
• The findings suggest that anomalous diffusion dynamics within the nanopore trap are crucial for understanding DNA escape.
• This work provides new perspectives on trapping and escape phenomena in similar biological and physical systems.