Liquid organelles mesh size

Range ~3-8 nm
Organism Nematode Caenorhabditis elegans
Reference Ming-Tzo Wei et al., Phase behaviour of disordered proteins underlying low density and high permeability of liquid organelles. Nature Chemistry 9, 1118–1125 (2017). doi:10.1038/nchem.2803 abstract & p.1123 left column bottom paragraphPubMed ID29064502
Method Abstract: "Here, [investigators] utilize a novel technique, ultrafast-scanning fluorescence correlation spectroscopy [FCS], to measure the molecular interactions and full coexistence curves (binodals), which quantify the protein concentration within LAF-1 droplets." P.1119 left column top paragraph: "[Investigators] also determine a structural length scale, the mesh size, which characterizes the molecular organization within droplets both in vitro and in vivo." P.1119 left column 2nd paragraph: "FCS is a powerful technique that relies on measuring the fluorescence intensity fluctuations of labelled molecules within small, femtolitre excitation volumes [ref 23]. FCS allows for precise measurements of molecular concentrations and diffusion coefficients, and has been employed for studying protein aggregation [ref 24]."
Comments Abstract: "[Investigators] find that LAF-1 and other in vitro and intracellular droplets are characterized by an effective mesh size of ∼3-8 nm, which determines the size scale at which droplet properties impact molecular diffusion and permeability." P.1123 left column bottom paragraph: "A surprising finding is that LAF-1 and its IDR [intrinsically disordered region] phase separate into liquid droplets of ultra-low protein concentration, which correspond to the semi-dilute regime. [Investigators] identify the characteristic mesh size within these permeable droplets to be ∼3–8 nm (Figs 3c and  5a,c). To account for this behaviour, [they] adapted an analytical model that explicitly accounts for the effects of conformational and chain density fluctuations."
Entered by Yair Harel
ID 114280