Mechanism of formation of lysozyme crystals in concentrated ammonium sulfate solution from concentration profiles and equilibria: Influence of the 2nd osmotic virial coefficient

We have modelled the nucleation of the orthorhombic crystal form of lysozyme and subsequent crystal growth from concentration profiles established during the measurement of equilibrium in concentrated solutions of ammonium sulphate. A BCF mechanism for the crystal growth has been assumed. The second osmotic virial coefficient is used to calculate the activity coefficient of the protein in solution. A steep decrease of B22 is predicted for salt molalities higher than 6.8 m.