Study of Metallothionein Aggregation in Dependence on Redox Conditions and Zinc Concentration by Using a Chip Capillary Electrophoresis
Abstract
Metallothioneins (MT) belong to cysteine-rich proteins with unique higher structure. MT structure is affected by metals concentration and redox conditions.
We used (.) capillary electrophoresis on chip (chip CE) and spectrophotometry to study MT structural changes in dependence on redox conditions and Zn(II) concentration (0, 5, 15, 25, 50 and 100 mu M). Reduced and oxidized apo-MT was prepared and Zn(II) binding was compared.
Reduced MT aggregated more readily than oxidized MT. By chip CE we quantified MT aggregation as a decrease of the MT monomer signal (Mw 15 kDa, migration time 26.5 s) and its ratio to total signal.
The dependences had an exponential character with R-2 higher than 0.94. Zn-MT interaction was 30 % faster during the first 15 min and 50 % faster during the whole experiment for reduced MT.