FIG. 3.
In vitro polymerization of CA in the presence of crowding agents. (A) the assay conditions were as follows: pH 7.8, 2.25 NaCl, 15 μM CA. The following crowding agent concentrations were used: circles, no crowding agent was added; triangles, 25 g/liter Ficoll; squares, 50 g/liter Ficoll; inverted triangles, 100 g/liter Ficoll; diamonds, 100 g/liter dextran. For clarity, only 1 in each 20 data points is represented (one in each five points for the first minutes at 50 g/liter or 100 g/liter Ficoll). Continuous lines represent the best fit to equation 1. (B) Relationship between the t50 obtained in the experiment shown in panel A and the Ficoll concentration. (C) Amount of CA polymers formed in the experiment shown in panel A, in the presence of either Ficoll (circles) or dextran (squares) at 100 g/liter, as a function of the total CA concentration. Linear extrapolation of the data gave the CA critical concentration.