ISSN:
0749-1581
Keywords:
13C NMR
;
2D NMR
;
Bleomycin A2
;
Bleomycin A2-zinc complex
;
Complete assignment
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
13C NMR spectra of free bleomycin A2 at pH 4 and 6.7 and of its zinc complex at pH 6.7 were completely assigned by making use of two-dimensional 1H—13C correlated spectroscopy. Differences in resonance positions between the spectra of the free bleomycin at pH 4 and 6.7 are observed for the β-hydroxyhistidine and the β-aminoalanine residues, obviously because of protonation/deprotonation of these moieties in the pH region considered. Also, shifts are observed for the carbon resonances of the gulose residue. Upon complex formation between zinc(II) and bleomycin large 13C shifts are observed for the carbon atoms in the pyrimidinepropionamide, β-hydroxyhistidine, β-aminoalanine, α-L-gulose and α-D-mannose fragments. Although for some residues the observed shifts correspond with the position of the zinc(II) binding sites in bleomycin proposed on the basis of earlier 1H NMR experiments, a simple correlation between the location of the zinc(II) binding sites and the 13C shifts cannot be drawn.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260260911
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