Mithramycin: a very strong metal chelating agent.
The interaction of mithramycin (MTR) with Ca2+, Cd2+, Tb3+, Gd3+, Li+, Na+ and K+ ions has been studied by circular dichroism and absorption spectroscopy. Mithramycin binds strongly to Ca2+, Cd2+, Tb3+ and Gd3+ forming a 1:4 Ca2+: MTR entities with a left-handed screw conformation. The concentration of Ca2+ present in water currently used being about 10 microM, this leads to the conclusion that, in most of the experiments reported in the literature, about 40 microM mithramycin were actually bound to Ca2+. Mithramycin also binds to Na+, forming entities with left-handed screw conformation, but not to K+ and Li+. None of these cations were able to promote the mithramycin-DNA interaction.
Demicheli
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Laboratoire de Chimie Bioinorganique, LPCB (URA CNRS 198) Université Paris Nord, Bobigny, France.
Garnier-Suillerot
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D000818:Animals; D002240:Carbohydrate Sequence; D002412:Cations / Q000378:metabolism; D002417:Cattle; D002614:Chelating Agents / Q000378:metabolism*; D002942:Circular Dichroism; D004247:DNA / Q000378:metabolism; D004533:Egtazic Acid / Q000737:chemistry; D008670:Metals / Q000378:metabolism*; D008969:Molecular Sequence Data; D008926:Plicamycin / Q000378:metabolism*
D002412:Cations; D002614:Chelating Agents; D008670:Metals; D004533:Egtazic Acid; D004247:DNA; D008926:Plicamycin