Fig. 1. Energy contribution per FG repeat unit in FG-FG partition.

a Scheme of the partition experiments: variants with different number (N) of connected perfect repeat units (as “guests”) were covalently coupled with a chemical fluorophore (Atto488), and the partition coefficient, P of each into a given “host” FG phase, formed by prf.GLFG_52×12^[+GLEBS], was measured by confocal laser scanning microscopy (CLSM) at 294 K. P is related to Gibbs free energy of partition (ΔG_part.) as described by Eq. 1. b Representative images from CLSM, showing the Atto488 signal of guests with indicated N at 150 mM NaCl. Upper two panels: XY scans with green and false colour, respectively. Lower panel: XZ scans with false colour showing an FG particle in each condition. Molar ratio of host: guest and scanning settings in the measurements were adjusted individually to cover wide dynamic ranges. For comparison herein, brightness of the FG phase in the images was normalized. c P against N was determined at different NaCl concentrations (C_NaCl) at a fixed temperature. Measurement for each condition was repeated three times with independent samples, and mean values are shown with S.D. as the error bars. Note that the logarithm of P scales linearly with N for all three concentrations of NaCl. A two-tailed p-value was computed by Analysis of Covariance (ANCOVA) to assess if the differences in slopes of the fits are statistically significant. No adjustment was made for multiple comparisons. This statistics analysis also applies to Figs. 4a, 5d, 6a and 7a. d ΔG_part. calculated from P (n = 3) by Eq. 1 was plotted against N for different C_NaCl. Mean values are shown with S.D. as the error bars. Each plot can be fitted with a linear function. e Slopes of ΔG_part. against N (i.e., $\frac{d{\Delta G}_{part.}}{dN}$) derived from (d) are plotted against C_NaCl. Data are presented as mean values with standard errors (S.E.) of fitting as the error bars.