PROTEIN ENGINEERING STRATEGIES IN EXAMINING PROTEIN-FOLDING INTERMEDIATES

Mutagenesis has proven to be a powerful tool for examining the structu res and stabilities of intermediates which appear during the folding o f globular proteins. Combining site-directed mutagenesis with other, m ore classical, methods of protein chemistry, such as chemical labeling and cleavage, has advanced the investigation of these transient, marg inally stable species. The high cooperativity of the folding reaction has been reduced by mutagenesis to produce a series of reactions invol ving stable, highly populated, partially folded forms. New insights in to inherently slow processes, such as proline isomerization reactions and disulfide bond rearrangements, have also resulted from protein eng ineering experiments.