Open Access113 Cd‐NMR investigation of a cadmium‐substituted copper, zinc‐containing superoxide dismutase from yeast
Author(s) -
KOFOD Pauli,
BAUER Rogert,
DANIELSEN Eva,
LARSEN Erik,
BJERRUM Morten J.
Publication year - 1991
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1991.tb16057.x
Subject(s) - superoxide dismutase , copper , zinc , chemistry , yeast , cadmium , nuclear magnetic resonance spectroscopy , metal , dismutase , enzyme , nmr spectra database , stereochemistry , biochemistry , spectral line , organic chemistry , physics , astronomy
113 Cd nuclear magnetic resonance spectroscopy has been used to investigate the metal binding sites of cadmium‐substituted copper,zinc‐containing superoxide dismutase from baker's yeast. NMR signals were obtained for 113 Cd(II) at the Cu site as well as for 113 Cd(II) at the Zn site. The two subunits in the dimeric enzyme were found to have identical coordination properties towards 113 Cd(II) as only two 113 Cd signals were found in 113 Cd 2 113 Cd 2 SOD. The difference between the chemical shifts of 113 Cd(II) at the Zn site when no copper is coordinated at the Cu site, and when Cu(I) or Cd(II) is coordinated, were found to be very small indicating that 113 Cd(II) must be bound to the same number and type of ligands in both cases. Furthermore, the spectra show that the rate of exchange of protein‐bound 113 Cd(II) and free 113 Cd 2+ is slow on the NMR time scale also at the Cu site. The present study suggests an explanation for the discrepancy in the literature regarding 113 Cd‐NMR investigations of bovine superoxide dismutase.