Protein solubility modeling.
A thermodynamic framework (UNIQUAC model with temperature dependent parameters) is applied to model the salt-induced protein crystallization equilibrium, i.e., protein solubility. The framework introduces a term for the solubility product describing protein transfer between the liquid and solid phase and a term for the solution behavior describing deviation from ideal solution. Protein solubility is modeled as a function of salt concentration and temperature for a four-component system consisting of a protein, pseudo solvent (water and buffer), cation, and anion (salt). Two different systems, lysozyme with sodium chloride and concanavalin A with ammonium sulfate, are investigated. Comparison of the modeled and experimental protein solubility data results in an average root mean square deviation of 5.8%, demonstrating that the model closely follows the experimental behavior. Model calculations and model parameters are reviewed to examine the model and protein crystallization process.
Agena
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SM
Biophysics ES76, National Aeronautics and Space Administration (NASA), Marshall Space Flight Center (MSFC), Huntsville, Alabama 35812, USA.
Pusey
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ML
Bogle
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ID
D000645:Ammonium Sulfate / Q000737:chemistry; D003208:Concanavalin A / Q000737:chemistry; D003460:Crystallization; D004305:Dose-Response Relationship, Drug; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008956:Models, Chemical; D009113:Muramidase / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D012995:Solubility; D013696:Temperature; D013816:Thermodynamics
D011506:Proteins; D003208:Concanavalin A; D012965:Sodium Chloride; D009113:Muramidase; D000645:Ammonium Sulfate