Protein Separation Flashcards
Methods of protein separation
1) Differential Solubility
2) Adsorption
3) Size
4) Eletrophoresis
Hydration Properties of Proteins
+ Water-holding capacity
+ Viscosity modifiers
+ Solubility
Protein-Protein Interactions
+ Gel formation
+ Precipitation
Surface Properties
+ Emulsifiers
+ Foaming
+ Surface Tension
Biochemical differences of proteins
+ Solubility
+ Size
+ Net Charge
+ Adsorption Character.
+ Affinity for other molecules
Separation by Differential Solubility
1) Salting Out
2) Isoelectric Point Precipitation
3) Solvent Fractionation
4) Denaturation of Other Proteins
Salting Out
proteins dissolve in water depends on the amount of hydrophilic amino acids present in that particular protein
No salt in solution
water molecules interact with the charged/hydrophilic amino acids of the protein
High Salt Concentration
Charged ion interact with water; Proteins molecule aggregate causing precipitation
Isoelectric Point
the pH at which a protein has no net charge in a solution
pH below pI
net charge is positive
pI is 0
less soluble
pH is above pI
net charge is negative
Proteins aggregate and precipitate at their pI because there is
no electrostatic repulsion
Solvent Fractionation
Proteins can be separated based on solubility differences in solvents or solvent mixtures
