Constrained dynamics of DNA oligonucleotides in phase-separated droplets

Biophys J. 2024 Jan 2:S0006-3495(23)04178-4. doi: 10.1016/j.bpj.2023.12.025. Online ahead of print.ABSTRACTUnderstanding the dynamics of biomolecules in complex environments is crucial for elucidating the effect of condensed and heterogeneous environments on their functional properties. A relevant environment - and one that can also be mimicked easily in vitro - is that of phase-separated droplets. While phase-separated droplet systems have been shown to compartmentalize a wide range of functional biomolecules, the effects of internal structuration of droplets on the dynamics and mobility of internalized molecules remain poorly understood. Here, we use fluorescence correlation spectroscopy (FCS), to measure the dynamics of short oligonucleotides encapsulated within two representative kinds of uncharged and charged phase-separated droplets. We find the internal structuration controls the oligonucleotide dynamics in these droplets, revealed by measuring physical parameters at high spatiotemporal resolution. By varying oligonucleotide length and salt concentrations (and thereby charge screening), we found that the dynamics are significantly affected in the non-charged droplets compared to the charged system. Our work lays the foundation for unravelling and quantifying the physical parameters governing biomolecular transport in the condensed environment.PMID:38169216 | DOI:10.1016/j.bpj.2023.12.025
Source: Biophysical Journal - Category: Physics Authors: Source Type: research