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A structurally driven analysis of thiol reactivity in mammalian albumins
Biopolymers (2011)
  • Ottavia Spiga, University of Siena
  • Domenico Summa, University of Siena
  • Simone Cirri, University of Siena
  • Andrea Bernini, University of Siena
  • Vincenzo Venditti
  • Matteo De Chiara, University of Siena
  • Raffaella Priora, University of Siena
  • Simona Frosail, University of Siena
  • Antonios Margaritis, University of Siena
  • Danila Di Giuseppe, University of Siena
  • Paolo Di Simplicio, University of Siena
  • Neri Niccolai, University of Siena
Abstract

Understanding the structural basis of protein redox activity is still an open question. Hence, by using a structural genomics approach, different albumins have been chosen to correlate protein structural features with the corresponding reaction rates of thiol exchange between albumin and disulfide DTNB. Predicted structures of rat, porcine, and bovine albumins have been compared with the experimentally derived human albumin. High structural similarity among these four albumins can be observed, in spite of their markedly different reactivity with DTNB. Sequence alignments offered preliminary hints on the contributions of sequence-specific local environments modulating albumin reactivity. Molecular dynamics simulations performed on experimental and predicted albumin structures reveal that thiolation rates are influenced by hydrogen bonding pattern and stability of the acceptor C34 sulphur atom with donor groups of nearby residues. Atom depth evolution of albumin C34 thiol groups has been monitored during Molecular Dynamic trajectories. The most reactive albumins appeared also the ones presenting the C34 sulphur atom on the protein surface with the highest accessibility. High C34 sulphur atom reactivity in rat and porcine albumins seems to be determined by the presence of additional positively charged amino acid residues favoring both the C34 S− form and the approach of DTNB.

Keywords
  • thiolation rate,
  • protein structure and function,
  • atom depth analysis,
  • MD simulations,
  • homology modeling
Publication Date
2011
Publisher Statement
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Citation Information
Ottavia Spiga, Domenico Summa, Simone Cirri, Andrea Bernini, et al.. "A structurally driven analysis of thiol reactivity in mammalian albumins" Biopolymers Vol. 95 Iss. 4 (2011)
Available at: http://works.bepress.com/vincenzo_venditti/10/