The Effect of Dimethyl Sulfoxide on Supercoiled DNA Relaxation Catalyzed by Type I Topoisomerases

Figure 2

The inhibition of CtTopo I catalyzed relaxation caused by DMSO. Electrophoretic analysis of relaxation products catalyzed by CtTopo I with different concentrations of DMSO. Lane 1: untreated pBR322 plasmid. Lanes 2 to 8: EcTopo I catalyzed relaxation products obtained by incubating 1.0 μg pBR322 plasmid with the concentrations of DMSO of 0% (Lane 2; no DMSO is added), 5% (Lane 3), 10% (Lane 4), 15% (Lane 5), 20% (Lane 6), 25% (Lane 7), and 30% (Lane 8). Lane 9: the mixture of 1.0 μg pBR322 with 20% (v/v).