Dresden 2020 – wissenschaftliches Programm

Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

BP: Fachverband Biologische Physik

BP 14: Focus: Phase Separation in Biological Systems II (joint session BP/CPP)

BP 14.9: Vortrag

Dienstag, 17. März 2020, 12:15–12:30, ZEU 250

Active growth and degradation of coacervate droplets controlled by enzymatic reactions — •Karina Nakashima, Alain André, Merlijn van Haren, and Evan Spruijt — Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands

Liquid-liquid phase separation plays an important role in the organization of biochemical processes in the cell. Control over phase separation by enzymatic reactions and the localization of biomolecules inside different droplet compartments is essential for many cellular functions. To elucidate the physicochemical principles that govern the nucleation, growth and coarsening of droplet organelles, we use coacervate droplets that we control by enzymatic reactions. Here, we present two experimental model systems, in which we achieve dynamic control over condensation and dissolution of coacervate droplets by changing either the charge density or the length of the constituent biomolecules. We track the coacervates by microscopy and follow their active growth and degradation at a single-droplet level. Our results indicate that droplets grow faster with increasing reaction-diffusion rate, while degradation of droplet material leads to a gradual dissolution of all droplets simultaneously. We also find that Ostwald ripening is suppressed in complex coacervates. We quantify the partitioning of all components in our system by HPLC and fluorescence labelling to support our results with a kinetic model. Our findings suggest that controlling phase separation in biological systems through enzymatic reactions may lead to a wide variety of droplet growth and degradation behaviours.