Study of inhibitory effect of mercury(II) ion on exonuclease IIIvia gel electrophoresis and microfluidic electrophoresis

The effect of mercury(II) ion on the exonucleolytic activity of Exo III was investigated by using microchip-based microfluidic electrophoresis coupled with polyacrylamide gel electrophoresis. This is the first report of this inhibitory effect with qualitative and quantitative analysis. With a series concentration of Exo III, the inhibition was quantitatively examined at various concentrations of mercuric ion ranging from 0 to 1 μM. For a given concentration of Exo III, the inhibition increased with increasing concentration of mercuric ions, whereas increasing concentration of Exo III hindered the inhibition activity. The inhibiting effect of 1 μM Hg2+ dropped significantly from (84.7 ± 1.95)% to (3.9 ± 1.25)% when the concentration of Exo III was increased from 0.02 to 0.5 units per μL. This study expands the application of microfluidic analytical methods to biochemistry and lays the foundation for the development of environmental research and genetic studies.