Figure 6.

Imino region of the ¹H NMR spectra of (A) p(UGG)₂U and (B) p(UGG)₄U at 25°C in the presence of (Aa, Ba, Ad, Bd) 50 mM KCl, 10 mM potassium phosphate and 0.1 mM EDTA, pH 6.8, (Ab, Bb) 150 mM NaCl, 10 mM sodium phosphate, 0.1 mM EDTA, pH 6.8, (Ac, Bc) 150 mM NH₄Cl, 10 mM Tris/HCl, 0.1 mM EDTA, pH 6.8 and (Ae, Be) HeLa cell extract. Asterisks indicate imino proton resonances of uridines. The poor S/N ratio observed for p(UGG)₄U is due to polymorphism or/and the presence of higher order structures.