BCHM 426 Lecture Notes - Lecture 6: Phenyl Group, Semipermeable Membrane, Ion Exchange
Document Summary
Have to exploit something that is different about your protein compared to all other proteins. *binding sites and substrates what ligands they have. Solubility of a protein is a complex function that depends upong the properties of the protein itself, the solvent, ionic strength, water ctivity, ph . A common coarse purification technique is to precipitate contaminating proteins. Can also be accomplished by changing the ph or using organic solvent. As the salt interacts with the water molecules, it decreases their mobility in the solution. The result is an increase of the hydrophobic effect. Proteins that would"ve never worked together now can, and that creates aggregation. This is different than protein-protein so we can take advantage of this. If you have protein a and b, you would set it to where protein a is insoluble, and b is soluble. Then do the same for b, when b is insoluble. Ammonium sulfate is the most commonly used salt.
