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.

Establishment of an interaction model of human apolipoprotein H with lipid monolayer by capillary SDS gel electrophoresis.

Apolipoprotein H (ApoH) is a plasma glycoprotein isolated from human serum. It plays a key role in the interaction with lipids. For the first time, the concentration of ApoH adsorbed on the lipid monolayer has been determined, and was done so using capillary electrophoresis. Based on this determination, an interaction model of ApoH and lipid monolayer was constructed, and this interaction is one of nonspecific adsorption. A neutral coated capillary (50 cm x 100 microm i.d.) and a negative voltage of 15 kV were used to separate ApoH. The calibration curve of ApoH was built using a detection limit of 50 microg/mL(-1) (near to 1 microM), and the RSD of the relative migration time of ApoH was 1.4% (n = 7).