Deglyco-peplomycin metal complexes on DNA fibers: a role of the sugar moiety for the stability and the orientation of the complexes

Abstract

Binding structures of metal complexes of deglyco-peplomycin (dPEP) on DNA were investigated by comparing dPEP complexes with those of bleomycin (BLM) using DNA fiber EPR spectroscopy. A low spin species of Fe(III)dPEP observed in the DNA pellet changed irreversibly to several high spin species after the fabrication of the DNA fibers. The g values of the high spin species were different from those of Fe(III)BLM. The high spin species could not be nitrosylated reductively to ON-Fe(II)dPEP, suggesting that some nitrogen atoms coordinated to the Fe(III) were displaced on the DNA fibers. On the other hand, O(2)-Co(II)dPEP remained intact on the fibers similarly to O(2)-Co(II)BLM but with an increased randomness in the orientation on the DNA. In contrast to Cu(II)BLM, a considerable amount of Cu(II)dPEP bound almost randomly on B-form DNA fibers. These results indicated that the sugar moiety in peplomycin or bleomycin is playing an important role in enhancing the stability of the metal-binding domain and in the stereospecificity of the binding on DNA.

Hydration Effect on the Intrinsic Magnetism of Natural Deoxyribonucleic Acid as Studied by EMR Spectroscopy and SQUID Measurements

“…But, no change in the signal shape and intensities were observed. This observation together with other researcher's reported results 33,[35][36][37] imply that the signals at g~2.0 are not originated from iron impurities. Figure 2 shows typical EMR spectra as obtained at room temperature from a dsDNA sample that was exposed to varying relative humidity.…”

DNA-fiber EPR spectroscopy as a tool to study DNA–metal complex interactions: DNA binding of hydrated Cu(II) ions and Cu(II) complexes of amino acids and peptides

“…Taking advantage of the information that can be provided by DNA-fiber EPR measurements, we have investigated the DNA binding structure of various paramagnetic complexes including Fe(III), Cu(II), and Co(II) complexes of bleomycin [12][13][14], deglycopepleomycin [15], cationic water-soluble porphyrins [16], Cu(II) complexes of cationic salen-type Schiff-bases [17], ternary Cu(II) complexes of phenanthroline and amino acids [18] , Cu(II) complexes of phenanthroline-derived ligands [19], and Cu(II) complexes of several triamines [20,21]. In this review, we focus on the interaction of Cu(II) ions, Cu(II) amino acid complexes, and Cu(II) peptide complexes with DNA [13,[22][23][24][25][26][27][28].…”

“…Since then, DNA-fibers have been utilized to investigate the double helical structure of DNA under various conditions and by a range of techniques. These techniques include X-ray diffraction [2][3][4], Raman scattering [5,6], and NMR [7][8][9][10][11], and as detailed herein, fiber EPR [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28].…”

Synthesis, characterization, DNA interaction, apoptosis and molecular docking of Cu(II) and Mn(II) complexes with endo‐norbornene‐cis‐5,6‐dicarboxylic acid

“…Manganese is an essential trace element, involved in numerous biological redox reactions . Manganese complexes play critical roles in dioxygen metabolism of many biological systems . In addition, 1,10‐phenanthroline and substituted derivatives can also coordinate with transition metals and disturb the functions of biological systems.…”