James K Bashkin
University of Missouri-St. Louis, USA
Title: Broad-spectrum binding to human papillomavirus DNA
Biography
Biography: James K Bashkin
Abstract
We describe the biophysical behavior of polyamides active against human papillomavirus (HPV) types 16, 18, and 31. The MWs of active polyamides are high, and we observed active uptake for human keratinocytes infected with HPV. We have measured binding constants for a group of active anti-HPV compounds on viral DNA, largely but not exclusively in the long control region (LCR). All of our most active polyamides to date contain guanidine and tetramethylguanidine N-termini, in partial mimicry of the natural product netropsin. These compounds include asymmetric hairpins as shown below, where not every heterocycle finds an analogous ring in the opposite strand of the hairpin. Binding constants were determined by quantitative DNase I footprinting and capillary electrophoresis. Binding constants do not correlate with antiviral activity, but there is a loose correlation between binding promiscuity and antiviral efficacy in cell culture. These and other recent results, including new observations of polyamide-DNA binding stoichiometry, are of interest. In particular, greater than 1:1 polyamide:DNA stoichiometries were observed. Evidence for such stoichiometries has been reported in the literature without comment, and here we will interpret these results as per our recent paper.1