title: Mobility-based correction for accurate determination of binding constants by capillary electrophoresis-frontal analysis.
abstract: Capillary electrophoresis frontal analysis (CE-FA) can be used to determine binding affinity of molecular interactions. However, its current data processing method mandate specific requirement on the mobilities of the binding pair in order to obtain accurate binding constants. This work shows that significant errors are resulted when the mobilities of the interacting species do not meet these requirements. Therefore, the applicability of CE-FA in many real word applications becomes questionable. An electrophoretic mobility-based correction method is developed in this work based on the flux of each species. A simulation program and a pair of model compounds are used to verify the new equations and evaluate the effectiveness of this method. Ibuprofen and hydroxypropyl-β-cyclodextrinare used to demonstrate the differences in the obtained binding constant by CE-FA when different calculation methods are used, and the results are compared with those obtained by affinity capillary electrophoresis (ACE). The results suggest that CE-FA, with the mobility-based correction method, can be a generally applicable method for a much wider range of applications.
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Cheng
authors.initials: C
authors.lastname: Qian
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Kovalchik
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: MacLennan
authors.affiliation: College of Chemistry and Material Sciences, Nanjing Normal University, Nanjing, Jiangsu, P. R. China.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver, BC, Canada.|College of Chemistry and Material Sciences, Nanjing Normal University, Nanjing, Jiangsu, P. R. China.
authors.forename: David D Y
authors.initials: DDY
authors.lastname: Chen
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D003198:Computer Simulation; D019075:Electrophoresis, Capillary / Q000379:methods*; D007052:Ibuprofen / Q000032:analysis; D011485:Protein Binding; D047392:beta-Cyclodextrins / Q000032:analysis* / Q000737:chemistry*
chemical_list: D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin; D007052:Ibuprofen
keywords: Capillary electrophoresis frontal analysis; Improved binding constant accuracy; Mobility corrected equation