Correlations between deoxyribonucleic acid structural parameters and calculated circular dichroism spectra.

Circular dichroism spectra are calculated for 68 different conformations of the bases in the double-stranded sequence of T-G-G-C-G-T-A-T-T-C-T and its complementary strand. All conformations are right-handed helices and include both published models and energy-minimized forms. Examination of the dependence of the circular dichroism band at 274 nm shows that the magnitude of the band is a linear function of both the helix winding angle and the base pair twist. Correlations of the magnitude of the circular dichroism with the distance between base pairs, the distance of the base pairs from the helix axis, or the tilt of the base pair relative to the helix axis are poorer.