Active growth and dissociation kinetics of bioinspired condensates

Living cells are organized into distinct sub-compartments to facilitate spatiotemporal regulation of biological reactions. Groundbreaking studies suggested that membraneless compartments of proteins and nucleic acids play such a crucial role and are formed through a liquid-liquid phase separation. Many in vitro models mimicking these compartments – hereafter called condensates – have emerged to understand their liquid-like properties. Here, we will investigate the growth and dissociation kinetics of condensates composed of phosphorylatable peptides and RNA, driven by enzymatic reactions. We will use time-resolved ultra-small-angle X-ray scattering (TR-USAXS) to probe the size evolution in the submicrometer scale. The collected data will constrain models allowing us to elucidate the molecular mechanisms, in particular whether the growth and dissociation are limited by enzymatic reactions or by diffusion.