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A systematic approach toward the analysis of drug–DNA interactions using Raman spectroscopy: The binding of metal‐free bleomycins A 2 and B 2 to calf thymus DNA
Author(s) -
Rajani C.,
Kincaid J. R.,
Petering D. H.
Publication year - 1999
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/1097-0282(1999)52:3<110::aid-bip20>3.0.co;2-#
Subject(s) - chemistry , dna , intercalation (chemistry) , bleomycin , raman spectroscopy , nucleotide , crystallography , stereochemistry , base pair , biochemistry , genetics , inorganic chemistry , biology , chemotherapy , gene , physics , optics
Bleomycins A 2 and B 2 are the two active components in the antineoplastic drug Blenoxane. DNA is targeted by this drug in cancer cells and the mode of action of this drug involves DNA binding. Ambiguity exists as to the way in which bleomycin binds to DNA. Raman spectroscopy was used to examine both calf thymus DNA and a bleomycin/DNA complex at two temperatures. A curvefitting technique was applied to these spectra for a spectral region obscured by many overlapping bands associated with the nucleotide bases in order to derive information about frequencies, bandwidths, and intensities of the vibrational modes in this region. This allowed identification and analysis of bands associated with specific assigned nucleotide base residues. Upon binding of bleomycin, several significant changes in bandwidth, intensities, and frequencies relative to uncomplexed DNA were observed consistently at both higher (30°C) and lower (19°C) temperature. The data presented here support at least a partial intercalation mode of binding for bleomycin that is temperature dependent and more pronounced at the more physiologically relevant temperature of 30° C. © 2001 John Wiley & Sons, Inc. Biopolymers (Nucleic Acid Sci) 52: 110–128, 1999