Solution precipitation method: separation is based on the principle that enzyme protein precipitates with some substances in solution under specific conditions. For example, the enzyme protein can be precipitated by adding salt or organic solvent, and then the precipitate can be separated from the supernatant by centrifugation.
Membrane filtration method: the enzyme protein is separated from other components by using different membrane pore sizes and molecular weight interception. For example, microporous membranes can be used to separate enzyme proteins from macromolecular substances (such as cell fragments, protein aggregates, etc.). ).
Chromatography: The enzyme protein was separated from other components by the difference between stationary phase and mobile phase. Commonly used chromatographic methods include gel filtration chromatography, ion exchange chromatography, affinity chromatography and countercurrent chromatography.
Electrophoresis: separation is carried out by using the mobility difference of enzyme protein in electric field. For example, enzyme proteins can be separated from other proteins by gel electrophoresis (such as polyacrylamide gel electrophoresis, polyacrylamide gel electrophoresis, etc.). ).
Elution method: the enzyme protein is eluted from the adsorbent by using the difference of interaction force between the enzyme protein and the adsorbent. For example, affinity chromatography can be used to separate enzymes from specific ligands such as metal ions, antibodies, etc. ).
The choice of these methods usually depends on the nature of the enzyme protein, the requirements of the target purification degree and the experimental conditions. In practice, it is often necessary to combine various methods to achieve high purification effect.