SATELLITE HOLE INVESTIGATION OF THE VIBRATIONAL-MODES OF 9-AMINOACRIDINE UPON BINDING TO DNA

The spectral features of satellite holes are used to investigate 9-ami noacridine-DNA interactions. The hole depths of the outer ring vibroni c modes are reduced more than that of the inner ring vibronic modes, i mplying that inner ring motion is less perturbed than outer ring motio n. As a result, the mode coupling between the inner ring and outer rin g is reduced upon binding to DNA. However, similar hole frequency and width of the satellite hole corresponding to the NH, mode upon binding to DNA imply that the amino group of 9-aminoacridine sits outside the DNA.