Proteins genetic variation, detection

As with the field of genetics as a whole, the two-hybrid assay is biased toward proteins. As variations of this assay, which can detect DNA, RNA, and small molecule binding, are now developed, it is exciting to imagine... 

Markers such as protein and blood group loci were initially used in the analysis of genetic traits however they were limited in utility due to low variation. Early in the 1980s these markers began to be replaced with DNA polymorphisms, initially RFLPs which are detected by the ability of a segment of DNA to be cut, or to not be cut, by a specific restriction enzyme. 

It is often difficult to establish that a recombinant protein manufactured in a novel cell system by genetically engineered approaches has the same tertiary structure as the authentic wild-type protein. Because detection by spectroscopic techniques such as circular dichroism (CD) of subtle conformational differences that may arise due to minor perturbations in the hydrophobic regions of a protein is often difficult, the observation of identical retention times for the rDNA and the wild-type protein by RPC and HIC procedures is a useful indicator of common three-dimensional structures. Moreover, when small structural variations arise due to amino acid residue additions, replacement, or chemical/enzymatic modifications, the use of RPC and HIC procedures under less denaturing elution conditions often favors the resolution of these species from the parent protein. The separation of recombinant Met -hGH from recombinant hGH is an example [385,404,415] where such approaches have been successfully applied. 

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