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. 2015 Jul 20;5:12082. doi: 10.1038/srep12082

Figure 1. SQDG inhibits relaxation activity of human topoisomerase I enzyme.

Figure 1

(a) Chemical structure of Sulfonoquinovosyl Diacylglyceride (SQDG). (b) DNA relaxation assay of topo I enzyme. Supercoiled pBS DNA was treated with topo I enzyme in the absence or presence of indicated concentrations of SQDG. CPT was used as control inhibitor. Lane 1, 100 fmol pBS DNA; lane 2, 100 fmol pBS DNA with 10 μM SQDG; lane 3, 100 fmol pBS DNA with 50 fmol of topo I enzyme; lanes 4 to 9, same as lane 3 but in the presence of indicated concentrations of SQDG; lane 10, same as lane 3 but in the presence of 5 μM CPT. Reactions were incubated at 37 °C for 30 minutes. (c) Preincubation DNA relaxation assay. Topo I was preincubated with indicated concentrations of SQDG or CPT for 5 minutes and then supercoiled pBS DNA was added. All the other conditions were same as DNA relaxation assay. (d) DNA relaxation assay of topo IIα enzyme. Lane 1, 100 fmol pBS DNA; lane 2, 100 fmol pBS DNA with 50 fmol of topo IIα enzyme; lanes 3 to 5, same as lane 2 but in the presence of indicated concentrations of SQDG. Complete scans of the different gels are presented in the Supplementary Figure S7.