Mass-spectrometric studies of the interactions of selected metalloantibiotics and drugs with deprotonated hexadeoxynucleotide GCATGC.
ESI tandem mass spectrometry is employed in a detailed study of the interactions of a hexameric duplex d(5'GCATGC) with three types of ligated first-row transition metal dications M(2+): metallated bleomycins, singly, doubly, and triply ligated metallophenanthrolines and [M(triethylenetetramine)](2+). The singly, doubly, and triply metallated species were found to dissociate by noncovalent separation into two strands with metal ions attached either to one or to both. Relative gas-phase stabilities of the double-stranded oligodeoxynucleotide (ODN)-M(2+) complexes were found to follow the order Mn(II) > Fe(II) > Co(II) > Ni(II) > Zn(II) > Cu(II). Overall, the presence of metal dications is found to increase the gas-phase stability of the duplex against noncovalent dissociation with the exception of one and three copper dications. An analysis of the dissociation pathways and relative gas-phase stabilities of the species that were investigated provided a basis for the assessment of the possible binding modes between duplex oligonucleotides and metallocomplexes.
Anichina
Janna
J
Department of Chemistry, York University, Toronto, Ontario, Canada M3J 1P3.
Bohme
Diethard K
DK
D001761:Bleomycin / Q000737:chemistry; D007364:Intercalating Agents / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D010618:Phenanthrolines / Q000737:chemistry; D053719:Tandem Mass Spectrometry
D007364:Intercalating Agents; D008670:Metals; D009838:Oligodeoxyribonucleotides; D010618:Phenanthrolines; D001761:Bleomycin