Figure 2.

Schematic presentation of ligand binding to human telomeric DNA fragment Tel22. The model mechanism describes Net, DP77, DP78 and TMPyP4 binding at various salt concentrations and temperatures where no unfolded Tel22 is present. It assumes the conversion between the folding intermediate, I, that contains no binding sites, and the folded intramolecular G-quadruplex structure, F, which contains a set of independent equivalent binding sites, N, characterized with the binding constant k_FL.