title: Specific ion effects on the electrophoretic mobility of small, highly charged peptides: a modeling study.
abstract: In this work, we use coarse-grained modeling to study the free solution electrophoretic mobility of small highly charged peptides (lysine, arginine, and short oligos thereof (up to nonapeptides)) in NaCl and Na2SO4 aqueous solutions at neutral pH and room temperature. The experimental data are taken from the literature. A bead modeling methodology that treats the electrostatics at the level of the nonlinear Poisson Boltzmann equation developed previously in our laboratory is able to account for the mobility of all peptides in NaCl, but not Na2SO4. The peptide mobilities in Na2SO4 can be accounted for by including sulfate binding in the model and this is proposed as one possible explanation for the discrepancy. Oligo arginine peptides bind more sulfate than oligo lysines and sulfate binding increases with the oligo length.
authors: Department of Chemistry, Georgia State University, Atlanta, GA, USA.
authors: Stuart A
authors: SA
authors: Allison
authors: Hengfu
authors: H
authors: Wu
authors: Tuyen M
authors: TM
authors: Bui
authors: Lac
authors: L
authors: Dang
authors: Giang H
authors: GH
authors: Huynh
authors: Tam
authors: T
authors: Nguyen
authors: Linda
authors: L
authors: Soegiarto
authors: Bi C
authors: BC
authors: Truong
mesh_terms: D004586:Electrophoresis; D008956:Models, Chemical; D010455:Peptides / Q000737:chemistry*
chemical_list: D010455:Peptides
keywords: Electrophoretic mobility; Ion effects; Modeling; Peptide mobility; Transport