Binding isotherms for CRB (○, n = 1), DA (□, n = 4), and EB (•, n = 2). Unwinding data are plotted according to Eq. 5. Interception of the ordinate at extrapolated infinite CN yields φ directly, and the negative inverse of the slope yields Ka. An additional hypothetical isotherm for DA (▪, n = 6) has been included to show that the intercept value of φ does not depend on the value of n used.