Fast Proton Titration Scheme for Multiscale Modeling of Protein Solutions

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

Proton exchange between titratable amino acid residues and the surrounding solution gives rise to exciting electric processes in proteins. We present a proton titration scheme for studying acid-base equilibria in Metropolis Monte Carlo simulations where salt is treated at the Debye-Huckel level. The method, rooted in the Kirkwood model of impenetrable spheres, is applied on the three milk proteins alpha-lactalbumin, beta-lactoglobulin, and lactoferrin, for which we investigate the net-charge, molecular dipole moment, and charge capacitance. Over a wide range of pH and salt conditions, excellent agreement is found with more elaborate simulations where salt is explicitly included. The implicit salt scheme is orders of magnitude faster than the explicit analog and allows for transparent interpretation of physical mechanisms. It is shown how the method can be expanded to multiscale modeling of aqueous salt solutions of many biomolecules with nonstatic charge distributions. Important examples are protein-protein aggregation, protein-polyelectrolyte complexation, and protein-membrane association.

Detaljer

Författare
  • Andre Azevedo Reis Teixeira
  • Mikael Lund
  • Fernando Luis Barroso da Silva
Enheter & grupper
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Teoretisk kemi
Originalspråkengelska
Sidor (från-till)3259-3266
TidskriftJournal of Chemical Theory and Computation
Volym6
Utgivningsnummer10
StatusPublished - 2010
PublikationskategoriForskning
Peer review utfördJa