Calculated number fraction of clathrin (solid lines) and weight fraction of protein (dashed lines) in self-assembled cages, as a function of the total AP concentration. The total clathrin concentration is indicated in the legend, in units of 10−7 molar; the APs bind to the ankle and TD of clathrin, and . Note that the fractions bound in cages do not increase monotonically but pass through a maximum, for reasons explained in the main text. To see this figure in color, go online.