Protein Precipitation
Protein precipitation refers to a variety of methods precipitating proteins for concentration or purification. The precipitated proteins can either be the target protein or other impurities. In contrast with other purification techniques such as chromatography, membrane separation, and ultracentrifugation, it is faster and much cheaper. It is commonly used as a pretreatment supplementary to other techniques. A wide range of protein precipitation methods is available at Creative BioMart Nanocage. Method types, mechanisms, and their usages are listed below. Different precipitation techniques can be used in combinations for a better purifying result.
Table 1. Protein precipitation services we offer
| Type | Mechanism | Usages |
|---|---|---|
| Thermal precipitation | Heat induces denaturation, aggregation, and precipitation of thermally unstable proteins. | Purification of target proteins with high thermal stability. Can be combined with isoelectric precipitation. |
| Ammonium sulfate (AS) precipitation | AS ions compete with proteins to bind to water molecules, leading to a decrease in protein solubility. It usually does not cause protein denaturation. | An initial step in the purification of a wide range of proteins. Protein concentration. |
| Polyethylene glycol (PEG) precipitation | The presence of PEG leads to a decrease in protein solubility. It has little tendency to denature proteins or interact with them. It is milder than organic precipitating agents. | Applicable in a wide range of proteins. Protein concentration |
| Polyethyleneimine (PEI) precipitation | PEI is like a soluble DEAE cellulose. It binds to nucleic acids or acidic proteins and precipitates with them. A high concentration of NaCl can elute bound protein from PEI. | Typically employed for nucleic acid removal. Suitable for removing acidic protein impurities from neutral or basic proteins. |
| Isoelectric precipitation | At the isoelectric point (pI) of a protein, repulsive electrostatic forces between proteins are reduced and they tend to aggregate and precipitate. | Applicable in a wide range of proteins. Can be combined with other precipitation techniques. |
Creative BioMart Nanocage specializes in protein nanocage purification. In the initial stage of protein nanocage purification, protein precipitation could be a desirable choice, as it is fast, easy, cheap, and highly scalable. For example, protein nanocages such as ferritin and HBc VLP outperform normal proteins in thermal stability, thermal precipitation can thus be employed to bulk remove host cell impurities.
Please let us know the aims and needs of your protein nanocage purification project through online inquiry. Our purification experts will immediately analyze your project and provide a feasible, inexpensive and fast purification plan. We guarantee that no damage would occur to the conformation of your protein nanocages in the purification process. In the protein precipitation experiment, we utilize orthogonal experiments to screen conditions and statistical methods to process data. Depending on the needs and aims of our customers, other purification techniques (chromatography, membrane separation, ultracentrifugation, etc) might be integrated into the purification plan. On completion of the purification, the purified protein nanocage and the result report will be delivered to customers without any delay.
Fig 1. Protein Precipitation Service Procedure
Reference
- Burgess, R. R. (2009). "Protein precipitation techniques." Methods in enzymology, 463, 331-342.
