Quantum-mechanical study of lead coordination in sulfur-rich proteins: mode and structure recognition in UV resonance Raman spectra.

ABSTRACT: Resonance Raman spectra are computed applying the weighted gradient methodology with CIS and DFT gradients to determine the characteristic spectral patterns for Hg(II) and Pb(II) loaded sulfur-rich proteins while excited to a characteristic LMCT electronic transition band. A framework of structure-spectrum relationships is established to assess lead coordination modes via vibrational spectroscopy. Illustrative calculations on Hg(II) complexes agree with experimental data demonstrating reliability and accuracy of the applied methodology. In contrast to Hg(II) complexes, a unique 3-center-4-electron hypervalent C(β)H···S interaction present in lead-sulfur complexes was established and suggested to play a key role in the strong preference for lead versus other metal ions in lead specific prot

SUBMITTER: Jarzecki AA 

PROVIDER: S-EPMC3321649 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature