Affinity Chromatography-II

We have studied basics of affinity purification during last lecture. The current lecture is continuation of last lecture and we will cover following:

1. Few specific examples of affinity purification in detail
2. Application of affinity chromatography in Proteomics

Because of advancement in Molecular Biology now it is possible to identify gene of a given protein. It is also possible to transfer the gene to other organism (for example E. coli ) in a vector (simply a vehicle to transfer foreign gene into organism or another cell ) and express in the same organism. Such proteins are called recombinant protein. Genetic manipulations are not scope of this course but students might have studied this in Molecular Biology course. Since purification of a protein can be a complex and time-consuming process so that the expression vectors are designed for higher level of expression of recombinant proteins with tags to facilitate the further purification. The DNA sequence codes for the protein are cloned in expression vectors at multiple cloning sites in continuation with tags either at N-terminal or C-terminal (Fig.1). These tags are also DNA sequences which code a small peptide or even a small protein to facilitate the purification of the recombinant protein. e.g. 6x His Tag or GST Tag are commonly used for purifying recombinant proteins.