Figure 6
From: Putative DNA G-quadruplex formation within the promoters of Plasmodium falciparum var genes
A: chemical structure of BOQ1. B: Mass spectrum of UpsB-Q-1 and the G-quadruplex ligand BOQ 1 in equimolar concentrations (10 μM). Only a [1:1] complex was observed. The upper panel shows a magnification on the DNA7- and the number of ammonium adducts (from zero to three). The mass difference between two adjacent ammonium adducts is around 2.43, indicating that the G-quadruplex is intramolecular.