The structure and function of the protein need to be maintained in a suitable pH environment. Therefore, the choice of pH buffer is very important during the preparation and purification of the protein. Only a suitable buffer can ensure the activity and structural stability of the protein.
Effect of buffer in protein purification process
There are many kinds of buffers for protein purification. While maintaining the pH of the system, it is necessary to ensure that the protein cannot be inactivated during the purification process, or to minimize the amount of protein inactivation, which must be maintained in every step of protein purification. Solubility and activity of protein.
Protein purification buffer requirements
The buffer in the protein purification process should not only prevent protein degradation, but also prevent protein aggregation, which has a significant impact on the experimental results. The following factors should be considered when selecting and reagent buffers: pH, buffer system, salt ions, reducing agents and stabilizers. Each of these factors should be optimized according to the purified target protein, and the activity of the target protein should be used as an evaluation criterion for optimization.
Understand protein stability conditions
There are many types of proteins, and different proteins adapt to different pH values. The buffer should be selected according to its optimal pH value. In many cases, the pH is 7.4, which is a mimic biological condition, and most proteins are stable at this pH. However, there are some exceptions, which require pH adjustment to keep the protein soluble and not degraded.
Commonly used buffers for protein purification
Commonly used buffers in the protein purification process include Tris, Tricine, Bis-Tris, MOPS, etc. Among them, Tris is commonly used. Its buffer range is close to physiological pH and has a low ionic strength. It is a good solvent for proteins. Can ensure the stability of the protein. It should be noted that when preparing the buffer, try to avoid the isoelectric point pl of the target protein. Because the protein has no electrostatic charge on its surface in the pH solution of its isoelectric point, the repulsive force between the hundred molecules is reduced, it is easy to aggregate, and the solubility is reduced.
Now the adaptation pH value, isoelectric point, and buffer range of the buffer to be purified can be found, and you can directly match it according to the corresponding requirements. Desheng is a manufacturer of in vitro diagnostic reagents, which can provide large-package pH buffers such as Tris, MOPS, Bicine, etc.