Monitoring the unfolding and refolding of creatine kinase by capillary zone electrophoresis.

Creatine kinase (ATP: creatine N-phosphotransferase; EC 2.7.3.2) plays a key role in the energy transport, muscle contraction, and reproduction of adenosine triphosphate (ATP). The activity of the enzyme is dependent on the correct folding of the peptide. We observed the unfolding and refolding processes of the creatine kinase of rabbit muscle, and concluded that traditional electrophoresis technology is unsuitable for the transient folding intermediates formed during protein unfolding and refolding. Capillary zone electrophoresis with diode array detection was used to monitor the unfolding and refolding of rabbit creatine kinase under different pretreatments and experimental conditions. This technique provides a simple, sensitive, and rapid approach to protein unfolding and refolding.