Without the metal ions, protein function can be adversely affected through perturbation of the conformation. Regulation of protein activity can be affected by the conformational changes caused by metal ion binding. Metal ions are also essential in electron transfer that is critical during energy conversion in the mitochondria and chloroplasts. The study of these essential interactions as well as the interactions of toxic metals with proteins, has been hampered by the lack of applicable analytical tools. Gel electrophoresis is extensively used in the analysis and purification of proteins and is critical to cancer research, toxicology, and the study of protein expression.
Electrophoresis is the movement of a molecule in a solution by the application of an electric field.
Electrophoresis commonly uses a gel made of a hydrophilic polymer. Current methods for the quantitation of proteins in gels often depend on the uptake of a dye by the protein. The stained proteins are then imaged and the darkness of the protein spot is correlated to the protein mass through the use of protein standards. The stain uptake is not stoichiometric and response is non-linear as the spot densities become saturated. Another analytical method used to measure a single metal or nonmetal element of a protein in a gel is radiography.