Figure 3.
CD spectra of a 12.5 μM solution of h-telo d[A(G3T2A)3G3T] in Tris buffer (pH 7.4), 3 equiv of helical oligomer 3, and in the absence of salt (solid line) or in the presence of 100 mM K+ (dashed line). The salt induces conformational changes in the quadruplex (240–300 nm region) which in turn induces a different handedness in 3 (350–450 region). The 240–300 region is essentially unchanged when 3 is absent (not shown).