Raman spectroscopy of an O(2)-Co(II)bleomycin-calf thymus DNA adduct: alternate polymer conformations.
Bleomycin (Blm) is an antitumor agent which binds to specific sequences of DNA and as HO(2)-Fe(III)Blm causes single and double strand cleavage. In the present investigation, binding of O(2)-Co(II)Blm to a native DNA polymer, calf thymus DNA, was examined using conventional Raman spectroscopy. O(2)-Co(II)Blm is a model for O(2)-Fe(II)Blm, the direct precursor of HO(2)-Fe(III)Blm. Although the DNA polymer retained a predominant B-form structure, Raman spectral evidence was obtained for localized structural changes to A, C and Z-DNA forms. The presence of these alternate DNA forms within B-DNA implied the presence of B/A, B/C and B/Z junctions. The observed changes in DNA secondary structure were attributed to perturbation of structural water resulting from binding of O(2)-Co(II)Blm within the minor groove.
Rajani
C
C
Department of Chemistry, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53211, USA.
Kincaid
J R
JR
Petering
D H
DH
D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000737:chemistry*; D001665:Binding Sites; D001761:Bleomycin / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000494:pharmacology; D002417:Cattle; D004247:DNA / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D018736:DNA Adducts / Q000737:chemistry* / Q000648:ultrastructure; D009690:Nucleic Acid Conformation / Q000187:drug effects; D013059:Spectrum Analysis, Raman; D014867:Water / Q000378:metabolism / Q000494:pharmacology
D000964:Antimetabolites, Antineoplastic; D018736:DNA Adducts; C030187:cobalt bleomycin; D014867:Water; D001761:Bleomycin; D004247:DNA; C427203:calf thymus DNA