Site-specific binding of chelerythrine to single cytosine and thymine bulges in DNA hairpins.

Chelerythrine exhibits pronounced antitumor and apoptosis activities. In order to provide insights into the molecular mechanism of its pharmacological effects, binding selectivity of chelerythrine to a series of single-base bulged DNA hairpins has been assayed by using spectrofluorometric technique. The results indicated that chelerythrine binds specifically to C- and T-bulge sites in DNA hairpins, while sanguinarine exhibits extremely weak binding selectivity to any single-base bulged DNA hairpins, although it has very similar structure with chelerythrine.