re-adsorption of Alb. This suggests that the reorganization of the proteins at the surface is likely to involve all the three families of proteins at the same time, in a way that is far more complicated than the usual two-states models based on kinetics equations with “transition” rate constants. Indeed, standard Langmuir kinetics would be able to predict the general trend of slowing down for increasing dilution [@Masel], but is unable to reproduce the three-steps kinetics, even in single protein adsorption, when conformational changes take place [@Adamczyk1995; @Quinn2008; @Bellion2008].

The second step starts, at $t^*_{X_P}$, when the total surface concentration is saturated (Fig. \[fdil300\]d). Therefore, new arriving Fib adsorbs in the “laying down” conformation if possible, or, with less energy gain but occupying less space, in the “standing up” conformation. Since at $t^*_{X_P}$ the IgG concentration is at its maximum, the probability that the new Fib adsorbs near a IgG (as in Fig.\[Fig1\]d) is high, determining a strong repulsion between the two charged proteins. This repulsion is stronger than the attraction of IgG with the surface, determining the displacement of the IgG and the decrease of $C^S_I$.

This displacement leaves enough space on the surface for the adsorption of the 