A conformational study of an aragonite-stabilizing peptide using molecular simulation. — ASN Events
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  3. A conformational study of an aragonite-stabilizing peptide using molecular simulation.

A conformational study of an aragonite-stabilizing peptide using molecular simulation. (#138)

Aaron H. Brown 1 , Tiffany R. Walsh 2
  1. Dept. of Chemistry and Centre for Scientific Computing, University of Warwick, Coventry, West Midlands, U.K.
  2. Institute for Frontier Materials, Deakin University, Waurn Ponds, Vic, Australia

In nacre (the mineral-rich material common to mollusk shells), proteins play an important role in exerting polymorph selection of CaCO3 minerals, stabilizing the aragonite polymorph of calcium carbonate1 . How this regulation works at the molecular level is unknown, because we do not know how the protein structure(s) relate to the function in this context. Determination of these protein structures in solution, while adsorbed at the mineral interface, is now possible, but difficult to accomplish in practice2 . Molecular simulation is a complementary tool for proposing and validating such structural data. As the first steps towards identifying the surface-adsorbed structures, we have focussed initially on probing the structure(s) of the N-terminal half of a known aragonite-stabilizing protein, n16. The resulting peptide (26 a.a.) is denoted n16N.  Previous work via solution-state NMR1  has probed  the conformational ensemble of n16N in solution both in pure water and in response to the presence of Ca2+ ions. These authors found in both cases that n16N exhibited a large degree of conformational lability, featuring an ensemble of random-coil structures; and thus n16N has been proposed as an intrinsically disordered peptide (IDP). In this work, we present results from our molecular simulations using the advanced sampling technique Replica Exchange with Solute Tempering (REST)3 45  in determining this ensemble of structures. We compare our findings against the existing experimental NMR data.

  1. S. Collino and J. S. Evans, Biomacromolecules, 9, 1909 (2008)
  2. P. A. Mirau, R. R Naik and P. Gehring, J. Amer. Chem. Soc., (2011), 133, p18243
  3. Moors, S.L.C. et al., J. Chem. Theory Comput., (2011), 7, p231
  4. Terakawa, T. et al., J. Comput. Chem., (2011), 32, p1228
  5. Wang, L. et al, J. Phys. Chem. B, (2011), 115, p9431