Chemical genetics introduced

T. A. Walsh (Dow AgroSciences, USA) introduced the concept of chemical genetics and described a successful example of identifying several novel herbicide targets using this strategy. 

Another relevant library-building concept that also emerged from the diversity of natural products assumes that such molecular scaffolds primarily hold the biological activity, and the side chains and functional groups only modify or fine-tune the interaction. Therefore, a new term was introduced by the Schreiber group, skeletal diversity (Kwon, Park, and Schreiber, 2002). Instead of increasing the overall structural diversity or dissimilarity, skeletal diversity is required in libraries involved in chemical genetics which can only be achieved by diversity-oriented synthesis (DOS) (Arya et al., 2005 Tan, 2005). 

Ballery, N., Desmadril, M., Minard, R, and Yon, J.M., 1993, Characterisation of an intermediate of phosphoglycerate kinase - chemical reactivity of genetically introduced cysteinyl residues during the folding process. Biochemistry 32 669-678. 

Insulin is one of the important pharmaceutical products produced commercially by genetically engineered bactera. Before this development, commercial insulin was isolated from animal pancreatic tissue. Microbial insulin has been available since 1982. The human insulin gene is introduced into a bacterium like E. coli. Two of the major advantages of insulin production by microorganisms are that the resultant insulin is chemically identical to human insulin, and it can be produced in unlimited quantities. 

The third purification procedure is based on the combination of temperature-triggered aggregation and affinity capture and has been used to not only purify proteins [50-54] but also other molecules [55, 56], and for the removal of pollutants from a solution [57-59]. For this procedure, ELP is conjugated to a capture reagent, which can be done either genetically or chemically. This procedure eliminates the need for cleavage of ELP after purification and introduces the potential to recycle the ELP. 

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