Dose-dependent analysis of VP1-dsDNA binding ability. Various concentrations of GST-VP1 were used to perform the dose-dependent analysis with a consistent concentration of plasmid pCAV (a) or linear dsDNA (b). The DNA fragment signals of the protein-DNA complex and differences in DNA migration patterns were more significant as the protein amount increased. Lane M, DNA ladder marker. Bold triangles indicate the protein-DNA complex formed by the tested protein and plasmids. Asterisks indicate the two conformations of plasmid DNAs, including the relaxed form (Form I) and a supercoiled form (Form II). The "pcDNA3.1xEcoRI" indicated generation of the linear form of pcDNA3.1 DNA digested by EcoRI