Figure 4.

Role of IDR sequence length in determining entropic force strength. (A) The variables d and θ (shown in Figure 1C) are varied discreetly to assess the number of allowed states Ω_T for the ensemble when tethered to the constraining surface. The color in each position on the grid represents the number of allowed states Ω_T from six different ϕ values. The total number of accessible states is used to calculate the entropic force strength for each construct. (B) Sequence length determines the entropic force strength of homopolymer-like IDRs. Red curve: exponential fit of the GS repeat entropic force strength. Gray dots: UGDH segments as measured in ref (13) show a similar entropic force as the equivalent GS repeat homopolymer. (C) Histogram of the entropic force of 96 PUMA scramble sequences. The red dashed line shows the entropic force strength of the same-length GS repeat sequence.