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.
Biophysics ES76, National Aeronautics and Space Administration (NASA), Marshall Space Flight Center (MSFC), Huntsville, Alabama 35812, USA.
S M
SM
Agena
M L
ML
Pusey
I D
ID
Bogle
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