Protein Unfolding and Conformational Studies by Capillary Electrophoresis

Sensitive yet selective techniques for characterizing protein unfolding are important for assessing the conformational stability of wild-type and recombinant protein. This review presents a summary of recent developments in protein unfolding by capillary electrophoresis (CE). Relative to conventional spectroscopic methods, CE offers a versatile microseparation format for performing unfolding studies using small amounts of protein mixtures based on thermal or chemical denaturation. The fundamental theory of protein unfolding in CE, as well as correction factors required to normalize non-specific changes in apparent mobility are examined in this review. The integration of in-capillary ligand stripping with dynamic protein unfolding by CE provides a convenient way to characterize holoproteins without sample pretreatment. CE is also a useful format for resolving protein conformational intermediates involving multimeric proteins or oligomers that is relevant to understanding the dynamics of misfolded proteins. This review covers protein unfolding and conformational studies from 1991-2006 with emphasis on recent developments in CE that highlight its significance as a complementary biophysical tool for protein characterization.