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Specific ion effects on the electrophoretic mobility of small, highly charged peptides: A modeling study
Author(s) -
Allison Stuart A.,
Wu Hengfu,
Bui Tuyen M.,
Dang Lac,
Huynh Giang H.,
Nguyen Tam,
Soegiarto Linda,
Truong Bi C.
Publication year - 2014
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.201400484
Subject(s) - chemistry , poisson–boltzmann equation , aqueous solution , electrophoresis , peptide , electrostatics , lysine , arginine , static electricity , chromatography , ion , biophysics , biochemistry , amino acid , organic chemistry , electrical engineering , biology , engineering
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 Na 2 SO 4 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 Na 2 SO 4 . The peptide mobilities in Na 2 SO 4 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.