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Article
Molecular Dynamics Simulation Studies of the Conformation and Lateral Mobility of a Charged Adsorbate Biomolecule: Implications for Estimating the Critical Value of the Radius of a Pore in Porous Media
Journal of Colloid and Interface Science
  • Xiaomin Zhang
  • Jee-Ching Wang, Missouri University of Science and Technology
  • Karol M. Lacki
  • Athanasios I. Liapis, Missouri University of Science and Technology
Abstract

The conformations, the values of the lateral transport coefficient of a charged biomolecule (desmopressin) in the adsorbed layer and in the liquid layers above the adsorbed layer, the potential energies of the interaction between the biomolecules located in different liquid layers with the charged solid surface and with the biomolecules in the adsorbed layer, the potential energies of the interaction between water molecules in the hydration layers surrounding the conformations of the biomolecules in different layers, as well as the structure and number of hydration layers between the different conformations of desmopressin, were determined by molecular dynamics simulation studies. The results show that the lateral mobility of the adsorbed desmopressin is approximately equal to zero and the value of the lateral transport coefficient of the biomolecule in the liquid layers located above the adsorbed layer increases as the distance of the liquid layer from the charged solid surface increases. But the values of the lateral transport coefficient of the biomolecule in the liquid layers above the adsorbed layer are lower in magnitude than the value of the transport coefficient of desmopressin along the direction normal to the charged solid surface in the liquid phase located above the vacant charged sites of the solid surface, and these differences in the values of the transport coefficients have important implications with respect to the replenishment of the biomolecules in the inner parts of a channel (pore), the overall rate of adsorption, and the form of the constitutive equations that would have to be used in macroscopic models to describe the mechanisms of mass transfer and adsorption in the pores of adsorbent media. Furthermore, a novel method is presented in this work that utilizes the information about the sizes of the conformations of the biomolecule in the adsorbed layer and in the liquid layers above the adsorbed layer along the direction that is normal to the charged solid surface, as well as the number and size of the hydration layers along the same direction, and could be used to estimate the value of the lower bound of the linear characteristic dimension of a pore (i.e., pore radius) in porous adsorbent media (e.g., porous adsorbent particles; skeletons of porous monoliths) in order to realize effective transport and overall adsorption rate.

Department(s)
Chemical and Biochemical Engineering
Keywords and Phrases
  • Conformation and Lateral Mobility of Biomolecules,
  • Critical Pore Radius,
  • Molecular Dynamics Simulation,
  • Transport and Adsorption of Biomolecules,
  • Biomolecules,
  • Molecular dynamics -- Simulation methods
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2005 Elsevier, All rights reserved.
Publication Date
10-15-2005
Publication Date
15 Oct 2005
Disciplines
Citation Information
Xiaomin Zhang, Jee-Ching Wang, Karol M. Lacki and Athanasios I. Liapis. "Molecular Dynamics Simulation Studies of the Conformation and Lateral Mobility of a Charged Adsorbate Biomolecule: Implications for Estimating the Critical Value of the Radius of a Pore in Porous Media" Journal of Colloid and Interface Science (2005) ISSN: 0021-9797
Available at: http://works.bepress.com/jee-ching-wang/14/