title: Molecular Dynamics Simulations Illuminate the Role of Counterion Condensation in the Electrophoretic Transport of Homogalacturonans.
abstract: Homogalacturonans (HGs) are polysaccharide copolymers of galacturonic acid and its methylesterified counterpart. The inter- and intramolecular distributions of the methylesterifed residues are vital behavior-determining characteristics of a sample's structure, and much experimental effort has been directed to their measurement. While many techniques are able to measure the sample-averaged degree of methylesterification (DM), the measurement of inter- and intramolecular charge distributions are challenging. Here, molecular dynamics (MD) simulations are used to calculate the electrophoretic mobilities of HGs that have different amounts and distributions of charges placed along the backbone. The simulations are shown to capture experimental results well, even for low-DM samples that possess high charge densities. In addition, they illuminate the role that local counterion condensation can play in the determination of the electrophoretic mobility of heterogeneous blocky polyelectrolytes that cannot be adequately described by a single chain-averaged charge spacing.
authors.affiliation: Institute of Fundamental Sciences, Massey University , Palmerston North, New Zealand.
authors.forename: Amir H
authors.identifier: 0000-0002-3819-677X
authors.initials: AH
authors.lastname: Irani
authors.affiliation: Institute of Fundamental Sciences, Massey University , Palmerston North, New Zealand.
authors.forename: Jessie L
authors.initials: JL
authors.lastname: Owen
authors.affiliation: Heidelberger Institut for Theoretische Studien, Heidelberg, Germany.
authors.forename: Davide
authors.initials: D
authors.lastname: Mercadante
authors.affiliation: Institute of Fundamental Sciences, Massey University , Palmerston North, New Zealand.|The MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington, New Zealand.
authors.forename: Martin A K
authors.initials: MA
authors.lastname: Williams
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D056004:Molecular Dynamics Simulation; D010368:Pectins / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*
chemical_list: D011108:Polymers; D010368:Pectins; C003181:polygalacturonic acid