Recombinant genes optimizing expression

To optimize transcription we must ensure that our recombinant gene is placed after a promoter (Fig. 24.6) that will be recognized by the RNA polymerase of the host cell where the gene is going to be expressed. There are two types of promoters that can be selected (i) constitutive promoters, which are expressed all the time and (ii) inducible promoters, where expression is turned off during culture growth and turned on upon the addition of an... 

While the initial goal of the discovery process is to express and purify the recombinant protein, without regard to cost and as quickly as possible, ultimately the production of a recombinant protein must be optimized to ensure that it can be produced at a reasonable cost. In most cases expression systems used to produce small quantities of recombinant protein for preliminary evaluation are not suitable to produce large quantities. Therefore, the gene inserted in the initial expression vectors must be systematically modified and recloned into vectors that can produce (1) a high yield of expressed protein, (2) stable host cell transfections, and (3) protein excretion. 

In summary, it can be concluded that the optimization of the expression of heterologous genes in animal cells deserves careful design. Firstly, the biological properties of the final product and the amount required for its further application (e.g. diagnostics or therapy) have to be considered. These two factors determine the strategy and expression system that best suit the needs of the recombinant product. Both the vector and the target... 

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