Genetic engineering offers the opportunity to modify the properties of proteins, thereby improving their purification properties. By inserting DNA sequence into the 3 ‘end or 5’ end of the target DNA, the amino acid sequence at both ends of the protein can be changed to act as a purified fusion protein. These fusions help the protein form inclusion bodies that stabilize the protein from protease attacks and give the protein specific purification properties for use in immunoaffinity, metal chelation, ion exchange, hydrophobic chromatography, and other separation operations. In addition, for proteins with known properties, changes in amino acids can introduce fragments with specific matrix adsorption affinity.
There are two very common labels on the market, namely histidine label and GST label, which can be inserted into proteins to form recombinant proteins. Welch has available packing materials for the purification of these two labeled proteins.
Histidine-tag (histidine-tag) is the most commonly used label for recombinant protein expression. Whether the expressed protein is soluble or the inclusion body can be purified by fixed metal ion affinity chromatography. 6×His-tag refers to a fusion tag composed of six histidine residues that can be inserted into the C-terminal or N-terminal of the target protein.
The most commonly used ligands for the purification of histidine labeled proteins are subamino-triacetic acid (NTA) and iminodiacetic acid (IDA), which can be purified by Ni Tanrose 6FF (NTA) or Ni Tanrose 6FF (IDA).
Glutathione S-transferase (GST) is an affinity label that can enhance the solubility of fusion proteins by labeling eukaryotic proteins with GST. In addition, GST-labeled proteins can be expressed at high levels in bacteria, but may form inclusion bodies due to protein aggregation. The GST label is generally added to the N or C terminal of the target protein.
GST has a relatively strong affinity for glutathione, which means that GST protein fuses can be captured on stationary substrates such as glutathione bonded packing materials. This binding property can be used for protein purification and capture of corresponding proteins through protein binding. Therefore, Welch GST Tanrose 4FF could be used to purify GST label proteins.