Figure 4.
Fluorescence titration curves for the binding of (A) AND (5.0 µM), (B) AMND (1.0 µM), (C) ADMND (1.0 µM) and (D) ATMND (0.5 µM) to 21-meric AP site-containing DNA duplexes [5′-GCA GCT CCC GXG GTC TCC TCG-3′/3′-CGT CGA GGG CNC CAG AGG AGC-5′, X = AP site (dSpacer), N = G, C, A or T]. Sample solutions were buffered to pH 7.0 with 10 mM sodium cacodylate, containing 100 mM NaCl and 1.0 mM EDTA. Excitation wavelength, 350 nm; temperature, 20°C. Analysis: AND, 392 nm; AMND, 400 nm; ADMND, 400 nm; ATMND, 403 nm.