Dresden 2020 – scientific programme
The DPG Spring Meeting in Dresden had to be cancelled! Read more ...
Parts | Days | Selection | Search | Updates | Downloads | Help
BP: Fachverband Biologische Physik
BP 14: Focus: Phase Separation in Biological Systems II (joint session BP/CPP)
BP 14.2: Talk
Tuesday, March 17, 2020, 09:45–10:00, ZEU 250
Protein condenstates as aging Maxwell fluids — •Louise Jawerth1, Elisabeth Fischer-Friedrich2, Anthony Hyman3, and Frank Julicher1 — 1Max Planck Institute for the Physics of Complex Systems — 2Biotec, TU Dresden, Tatzberg 47-49, 01307 Dresden, Germany — 3Max Planck Institute of Molecular Cell Biology and Genetics
Protein condensates (PC) are intracellular compartments that segregate material without the use of a membrane. The liquid-like behavior of the condensates is a defining characteristic and the material properties of condensates are tuned to their biological function. It has become increasingly clear that some condensates do not have time-independent material properties, but can, instead, transition to more solid, gel-like materials. Here, we present our efforts to quantify these new materials as they age in vitro. We measure the visco-elastic material properties of several proteins by means of a combination of active and passive microrheology. At early times, we find that the droplets behave much like simple liquids but gradually become more elastic. Surprisingly, the changing mechanical properties can all be scaled onto a single master curve using one characteristic time scale which grows as the sample ages. We consider protein condensates as soft glassy materials with age dependent material properties that we call Maxwell glasses. To gain insight into the molecular origins of this behavior, we present electron microscopy images of the condensates at different ages. Furthermore, we demonstrate how salt concentration tunes the characteristics of the aging process.