Denaturant-gradient gel electrophoresis: technical aspects and practical applications Review Article

In denaturant-gradient gel electrophoresis (DGGE) proteins are run across a varying urea concentration in order to investigate their unfolding/refolding behavior in the presence of a chaotropic agent. The main parameter to characterize such denaturation curves is Cm, the urea concentration at one-half transition from the fast mobility of the folded, compact structure to the slow mobility of the unfolded molecule, with its much larger hydrodynamic volume. Comparison of Cm ranks proteins on the score of their structural stability. Likewise, the free energy of the transition and its cooperativity, the reversibility of the process and the presence of intermediate conformations may be evaluated from the parameters of the curve.