Biostructural chemistry of magnesium. Regulation of mithramycin-DNA interactions by Mg2+ coordination

The Crucial Role of Divalent Metal Ions in the DNA-Acting Efficacy and Inhibition of the Transcription of Dimeric Chromomycin A3

“…As shown in Figures 2A and 2B , the CD spectra of Chro were scanned from 200 to 520 nm in the presence of various divalent metal ions, including Mg(II), Fe(II), Co(II), and Ni(II), without and with DNA binding. Based on the results of previous studies [30], [31], the spectral features in the 250–300 nm region most likely arose from the absorption assigned to the aglycon chromophore ring of Chro that was polarized along the long axis. Therefore, the intensity in the 250–300 nm region is indicative of a transition between the monomer and dimer of drugs in the aureolic family.…”

The Crucial Role of Divalent Metal Ions in the DNA-Acting Efficacy and Inhibition of the Transcription of Dimeric Chromomycin A3

“…As shown in Figures 2A and 2B , the CD spectra of Chro were scanned from 200 to 520 nm in the presence of various divalent metal ions, including Mg(II), Fe(II), Co(II), and Ni(II), without and with DNA binding. Based on the results of previous studies [30], [31], the spectral features in the 250–300 nm region most likely arose from the absorption assigned to the aglycon chromophore ring of Chro that was polarized along the long axis. Therefore, the intensity in the 250–300 nm region is indicative of a transition between the monomer and dimer of drugs in the aureolic family.…”

Mithramycin forms a stable dimeric complex by chelating with Fe(II): DNA-interacting characteristics, cellular permeation and cytotoxicity

“…The occurrence of two isobestic points at 285 and 402 nm remaining basically unchanged demonstrates the presence of one-mode conformation alternation of Mith by binding with Mg(II). The feature in the 250–300 nm region arises from absorption assigned to the aglycon chromophore ring of the free Mith and is polarized along the long axis (24,25). However, the spectral changes were particularly pronounced in the UV region, with decreased negative peak intensity at 300 nm, with an ultimate inversion of the band in the 250–300 nm region at high concentration of Mg(II) ion.…”

Studies of Sequence-Specific DNA Binding, DNA Cleavage, and Topoisomerase I Inhibition by the Dimeric Chromomycin A3 Complexed with FeII

“…As shown in Figure 2, the CD spectra of Chro were scanned from 200 to 520 nm in the presence of increasing concentrations (0.00-0.10 mM) of Fe II . The spectral features in the 250-300 nm most likely arose from the absorption assigned to the aglycon chromophore ring of Chro that was polarized along the long axis based on the studies of Mith (25,26). The occurrence of one isosbestic point at 285 nm remaining basically unchanged demonstrates the presence of one-mode conformation alteration of Chro upon binding to Fe II .…”

The Crucial Role of Divalent Metal Ions in the DNA-Acting Efficacy and Inhibition of the Transcription of Dimeric Chromomycin A3

“…As shown in Figures 2A and 2B , the CD spectra of Chro were scanned from 200 to 520 nm in the presence of various divalent metal ions, including Mg(II), Fe(II), Co(II), and Ni(II), without and with DNA binding. Based on the results of previous studies [30], [31], the spectral features in the 250–300 nm region most likely arose from the absorption assigned to the aglycon chromophore ring of Chro that was polarized along the long axis. Therefore, the intensity in the 250–300 nm region is indicative of a transition between the monomer and dimer of drugs in the aureolic family.…”

Mithramycin forms a stable dimeric complex by chelating with Fe(II): DNA-interacting characteristics, cellular permeation and cytotoxicity

“…The occurrence of two isobestic points at 285 and 402 nm remaining basically unchanged demonstrates the presence of one-mode conformation alternation of Mith by binding with Mg(II). The feature in the 250–300 nm region arises from absorption assigned to the aglycon chromophore ring of the free Mith and is polarized along the long axis (24,25). However, the spectral changes were particularly pronounced in the UV region, with decreased negative peak intensity at 300 nm, with an ultimate inversion of the band in the 250–300 nm region at high concentration of Mg(II) ion.…”

Studies of Sequence-Specific DNA Binding, DNA Cleavage, and Topoisomerase I Inhibition by the Dimeric Chromomycin A3 Complexed with FeII

“…As shown in Figure 2, the CD spectra of Chro were scanned from 200 to 520 nm in the presence of increasing concentrations (0.00-0.10 mM) of Fe II . The spectral features in the 250-300 nm most likely arose from the absorption assigned to the aglycon chromophore ring of Chro that was polarized along the long axis based on the studies of Mith (25,26). The occurrence of one isosbestic point at 285 nm remaining basically unchanged demonstrates the presence of one-mode conformation alteration of Chro upon binding to Fe II .…”

The Crucial Role of Divalent Metal Ions in the DNA-Acting Efficacy and Inhibition of the Transcription of Dimeric Chromomycin A3

“…As shown in Figures 2A and 2B , the CD spectra of Chro were scanned from 200 to 520 nm in the presence of various divalent metal ions, including Mg(II), Fe(II), Co(II), and Ni(II), without and with DNA binding. Based on the results of previous studies [30], [31], the spectral features in the 250–300 nm region most likely arose from the absorption assigned to the aglycon chromophore ring of Chro that was polarized along the long axis. Therefore, the intensity in the 250–300 nm region is indicative of a transition between the monomer and dimer of drugs in the aureolic family.…”

Mithramycin forms a stable dimeric complex by chelating with Fe(II): DNA-interacting characteristics, cellular permeation and cytotoxicity

“…The occurrence of two isobestic points at 285 and 402 nm remaining basically unchanged demonstrates the presence of one-mode conformation alternation of Mith by binding with Mg(II). The feature in the 250–300 nm region arises from absorption assigned to the aglycon chromophore ring of the free Mith and is polarized along the long axis (24,25). However, the spectral changes were particularly pronounced in the UV region, with decreased negative peak intensity at 300 nm, with an ultimate inversion of the band in the 250–300 nm region at high concentration of Mg(II) ion.…”

Studies of Sequence-Specific DNA Binding, DNA Cleavage, and Topoisomerase I Inhibition by the Dimeric Chromomycin A3 Complexed with FeII

“…As shown in Figure 2, the CD spectra of Chro were scanned from 200 to 520 nm in the presence of increasing concentrations (0.00-0.10 mM) of Fe II . The spectral features in the 250-300 nm most likely arose from the absorption assigned to the aglycon chromophore ring of Chro that was polarized along the long axis based on the studies of Mith (25,26). The occurrence of one isosbestic point at 285 nm remaining basically unchanged demonstrates the presence of one-mode conformation alteration of Chro upon binding to Fe II .…”