Overview of the recombinant proteins purification by affinity tags and tags exploit systems
The advancement in protein expression systems causes yield of each peptide intracellular at least as host. The yield proteins should be purified eventually to provide use possibility or study on them. Therefore rapid and thereby economical purification of an active biological recombinant protein from other cell contents is considered as one of greatest challenges in Biotechnology field .
Purification of target protein or enzyme can be facilitated through the integration of genetic sequences with an affinity tag. In this case the tag to the target protein and the protein are expressed as a single unit and the protein can be isolated through one of purification methods by tag from other cellular contents. The affinity tags are commonly used in research laboratories because they can be used to purify wide range of high purification.
One of the important limits of affinity tags is unintended effect of tag on the natural function of the protein, its physicochemical properties and also the next applications. So separating tag after the purification process of target protein is essential. While the process is done through specific endopeptidase, the incoming cost prevents the technique of large-scale application. In addition, applied peptidase should be separated
From protein within isolation process which the same matter increases labor costs further and prevents application of these tags in industrial scale. Therefore proper replacement is emphasized for enzymatic removal of purification tags.
Keywords: protein purification; recombinant proteins; self-cleavable tags; Intein tags; nonchromatographic methods