Dresden 2020 – scientific programme

The DPG Spring Meeting in Dresden had to be cancelled! Read more ...

Parts | Days | Selection | Search | Updates | Downloads | Help

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 47: Focus: Phase Separation in Biological Systems II (joint session BP/CPP)

CPP 47.1: Talk

Tuesday, March 17, 2020, 09:30–09:45, ZEU 250

Salt-dependent rheology and surface tension of protein condensates using optical traps — Louise Jawerth¹, Mahdiye Ijavi¹, Martine Ruer¹, Shambaditya Saha¹, Marcus Jahnel^1,4, Anthony Hyman¹, Frank Jülicher^2,3, and •Elisabeth Fischer-Friedrich^4,5 — ¹MPI CBG, Pfotenhauerstr. 108, 01307 Dresden, Germany — ²MPI PKS, Nöthnitzerstr. 38, 01187 Dresden, Germany — ³Center for Systems Biology Dresden, Pfotenhauerstraße 108, 01307 Dresden, Germany — ⁴Biotec, TU Dresden, Tatzberg 47-49, 01307 Dresden, Germany — ⁵Excellence Cluster Physics of Life, TU Dresden, Dresden, Germany

An increasing number of proteins with intrinsically disordered domains have been shown to phase separate in buffer to form liquid-like phases. These protein condensates serve as simple models for the investigation of the more complex membrane-less organelles in cells. To understand the function of such proteins in cells, the material properties of the condensates they form are important. However, these material properties are not well understood. Here, we develop a novel method based on optical traps to study the frequency-dependent rheology and the surface tension of PGL-3 condensates as a function of salt concentration. We find that PGL-3 droplets are predominantly viscous but also exhibit elastic properties. As the salt concentration is reduced, their elastic modulus, viscosity and surface tension increase. Our findings show that salt concentration has a strong influence on the rheology and dynamics of protein condensates suggesting an important role of electrostatic interactions for their material properties.