Polymerization dynamics of double-stranded biopolymers: chemical kinetic approach

TL;DR

This paper presents a theoretical chemical kinetic model for double-stranded biopolymer polymerization, providing exact analytical expressions for growth dynamics and comparing them with approximate models, with applications to actin filaments.

Contribution

It introduces a detailed chemical kinetic approach that explicitly considers microscopic structural details and lateral interactions in double-stranded polymers.

Findings

Derived exact formulas for growth velocity and dispersion of two-stranded polymers.

Compared exact models with approximate multi-layer models for accuracy.

Applied the model to analyze experimental data on actin filament growth.

Abstract

The polymerization dynamics of double-stranded polymers, such as actin filaments, is investigated theoretically using simple chemical kinetic models that explicitly take into account some microscopic details of the polymer structure and the lateral interactions between the protofilaments. By considering all possible molecular configurations, the exact analytical expressions for the growth velocity and dispersion for two-stranded polymers are obtained in the case of the growing at only one end, and for the growth from both polymer ends. Exact theoretical calculations are compared with the predictions of approximate multi-layer models that consider only a finite number of the most relevant polymer configurations. Our theoretical approach is applied to analyze the experimental data on the growth and fluctuations dynamics of individual single actin filaments.