Sequential binding-unbinding based specific interactions influence exchange dynamics and size distribution of protein condensates

TL;DR

This paper investigates how different binding-unbinding interaction mechanisms between proteins affect the exchange dynamics, size distribution, and physical properties of biomolecular condensates, revealing the importance of interaction lifetime distributions.

Contribution

It introduces a heuristic model comparing single-step and multistep binding interactions, showing their impact on condensate properties through combined modeling and simulations.

Findings

Sequential interactions lead to power-law lifetime distributions.

Interaction mechanisms influence condensate fluidity and aging.

Differences in lifetime distributions affect size and exchange dynamics.

Abstract

The interaction lifetimes between condensate-forming biomolecules can dictate both the specificity of the condensate-forming species as well as the fluidity and exchange dynamics of these condensates. Using a heuristic modeling approach, we show that single-step vs. sequential, multistep binding-unbinding interactions between proteins can lead to similar average interaction lifetimes, but with either exponential or truncated power-law-like lifetime distributions, respectively. Combining this model with Brownian dynamics simulations, we find that the differences in these lifetime distributions influence the features of condensates, such as their fluidic nature, aging, and size distribution.