th  - 1987 - 51st ENC Conference

WKIO
IH, IsC, AND ISN NMR STUDIES OF METAL COMPLEXES OF BLEOMYCIN
Ian J. Mclennan* Michael P Gamcslk, Susanta K. Sarkar, Ad Bax t , and
I °
Jerry D. Gllckson, Depar ~ment of Radiology, The Johns Hopkins University
School of Medicine, Baltimore MD 21205 and SNatlonal Institutes of Health,
Bethesda MD 20892.
The solution conformation of the Zn(II) bleomycin complex has been
studied by ZH, IsC, and ISN NMR. As part of the study we have performed
rotating frame NOE experiments in both H20 and D20. The Zn(II) bleomycln
complex has been found to be partlcularly amenable to rotating frame
experiments since the TlP'S of the complex are long (-50ms) at 4°C. The
complete assignment of the IH spectrum of the Zn(II) bleomycln complex has
been accomplished by COSY-llke experiments utilizing Hartman-Hahn
polarization transfer. The complete assignment of the IsC spectrum of the
Zn(II) bleomycin complex has been accomplished using the RELAY method
(Lerner and Bax (1986) J. Magn. Reson. 69, 375). The assignment of the
peptide amlde nitrogens in free bleomycin and the Zn(II) bleomycin complex
was accomplished by IH-16N multiple quantum experiments. The results from
these experiments are discussed in terms of a probable solution
conformation of the Zn(II) bleomycln complex.