Structural characterization of Ru-bleomycin complexes by resonance Raman, circular dichroism, and NMR spectroscopy.
A series of spectroscopic techniques including absorption and CD spectra, resonance Raman spectra, and (1)H NMR as well as electrospray mass spectrometry have shown that Ru(II) ion binds to bleomycin, forming an equimolar complex, similarly to Fe(II), i.e., via the secondary amine nitrogen, the pyrimidine ring nitrogen, the deprotonated peptide bond nitrogen of the histydyl residue, and the histidine imidazole nitrogen, which are bound in the equatorial positions, and the alpha-amino nitrogen of beta-aminoalanine, which coordinates in the apical position above pH 7. The reaction of Ru(II)-BLM with O(2), H(2)O(2),or PhIO leads to formation of the oxy species in which only one oxygen atom is bound to metal ion. According to our data, the reaction of Ru(II)-BLM complex with oxygen species leads to different product than that suggested for Fe(II)-BLM. The formation of the BLM-Ru-O-Ru-BLM dimeric unit, similar to that found for sterically unhindered Ru porphyrins, seems to be the most likely.
Mouzopoulou
B
B
Laboratoire de Physicochimie Biomoléculaire et Cellulaire, Université Paris Nord, Bobigny 93017, France.
Kozlowski
H
H
Katsaros
N
N
Garnier-Suillerot
A
A
D000900:Anti-Bacterial Agents / Q000737:chemistry*; D001761:Bleomycin / Q000737:chemistry*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002942:Circular Dichroism; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013059:Spectrum Analysis, Raman; D013237:Stereoisomerism
D000900:Anti-Bacterial Agents; D009942:Organometallic Compounds; D001761:Bleomycin; D012428:Ruthenium