Download MendeleyA charge polarization model for the metal-specific activity of superoxide dismutases.
Barwinska-Sendra, A., Basle, A., Waldron, K.J., Un, S.(2018) Phys Chem Chem Phys 20: 2363-2372
- PubMed: 29308487
- DOI: https://doi.org/10.1039/c7cp06829h
- Primary Citation of Related Structures:
5N56, 5N57 - PubMed Abstract:
The pathogenicity of Staphylococcus aureus is enhanced by having two superoxide dismutases (SODs): a Mn-specific SOD and another that can use either Mn or Fe. Using 94 GHz electron-nuclear double resonance (ENDOR) and electron double resonance detected (ELDOR)-NMR we show that, despite their different metal-specificities, their structural and electronic similarities extend down to their active-site 1 H- and 14 N-Mn(ii) hyperfine interactions. However these interactions, and hence the positions of these nuclei, are different in the inactive Mn-reconstituted Escherichia coli Fe-specific SOD. Density functional theory modelling attributes this to a different angular position of the E. coli H171 ligand. This likely disrupts the Mn-H171-E170' triad causing a shift in charge and in metal redox potential, leading to the loss of activity. This is supported by the correlated differences in the Mn(ii) zero-field interactions of the three SOD types and suggests that the triad is important for determining metal specific activity.
Organizational Affiliation:
Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK. kevin.waldron@newcastle.ac.uk.
