DNA interactions of antitumor cisplatin analogs containing enantiomeric amine ligands.
Modifications of natural DNA and synthetic oligodeoxyribonucleotide duplexes in a cell-free medium by analogs of antitumor cisplatin containing enantiomeric amine ligands, such as cis-[PtCl(2)(RR-DAB)] and cis-[PtCl(2)(SS-DAB)] (DAB = 2,3-diaminobutane), were studied by various methods of molecular biophysics and biophysical chemistry. These methods include DNA binding studies by pulse polarography and atomic absorption spectrophotometry, mapping of DNA adducts using transcription assay, interstrand cross-linking assay using gel electrophoresis under denaturing conditions, differential scanning calorimetry, chemical probing, and bending and unwinding studies of the duplexes containing single, site-specific cross-link. The major differences resulting from the modification of DNA by the two enantiomers are the thermodynamical destabilization and conformational distortions induced in DNA by the 1,2-d(GpG) intrastrand cross-link. It has been suggested that these differences are associated with a different biological activity of the two enantiomers observed previously. In addition, the results of the present work are also consistent with the view that formation of hydrogen bonds between the carbonyl oxygen of the guanine residues and the "quasi equatorial" hydrogen of the cis amine in the 1, 2-d(GpG) intrastrand cross-link plays an important role in determining the character of the distortion induced in DNA by this lesion.
Malina
J
J
Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic.
Hofr
C
C
Maresca
L
L
Natile
G
G
Brabec
V
V
D000588:Amines / Q000737:chemistry; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000494:pharmacology*; D001483:Base Sequence; D001665:Binding Sites; D055592:Biophysical Phenomena; D001703:Biophysics; D002152:Calorimetry, Differential Scanning; D002417:Cattle; D002945:Cisplatin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D003432:Cross-Linking Reagents; D004247:DNA / Q000737:chemistry* / Q000187:drug effects* / Q000235:genetics; D018736:DNA Adducts / Q000737:chemistry; D066298:In Vitro Techniques; D008024:Ligands; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D013237:Stereoisomerism; D013816:Thermodynamics; D014158:Transcription, Genetic
D000588:Amines; D000970:Antineoplastic Agents; D003432:Cross-Linking Reagents; D018736:DNA Adducts; D008024:Ligands; D004247:DNA; D002945:Cisplatin