Rheology of aging protein condensates

Biophysics Protein condensates that form by undergoing liquid-liquid phase separation will show changes in their rheological properties with time, a process known as aging. Jawerth et al. used laser tweezer–based active and microbead-based passive rheology to characterize the time-dependent material properties of protein condensates (see the Perspective by Zhang). They found that condensate aging is not gelation of the condensates, but rather a changing viscoelastic Maxwell liquid with a viscosity that strongly increases with age, whereas the elastic modulus stays the same. Science , this issue p. [1317][1]; see also p. [1271][2] [1]: /lookup/doi/10.1126/science.aaw4951 [2]: /lookup/doi/10.1126/science.abe9745