title: Characterization of bovine serum albumin-tryptophan interaction by capillary isoelectric focusing with whole column imaging detection.
abstract: Capillary isoelectric focusing (cIEF) with whole column imaging detection (WCID) was explored for the characterization of bovine serum albumin (BSA)-tryptophan interaction, to further understand protein-drug interactions. The BSA-tryptophan interaction was dynamically monitored by cIEF-WCID, to provide the cIEF profiles of the BSA-tryptophan interaction system at different focusing times. Our study demonstrated that the cIEF behavior of BSA can serve as a probe into the study of BSA-tryptophan interaction, through monitoring the change in its cIEF profile when the interaction occurred. The study illustrated that the BSA peak split due to the BSA-tryptophan interaction, and the peak of BSA-tryptophan complex was clearly identified in the cIEF electropherograms. By comparing the cIEF profiles of BSA/L-tryptophan and BSA/D-tryptophan, respectively, our study demonstrated that BSA interacted with the enantiomers of tryptophan with a chiral recognition. L-Tryptophan demonstrated a very strong interaction with BSA, while D-tryptophan exhibited a much weaker interaction with BSA. The effects of the BSA concentration, the tryptophan concentration, the focusing time and the incubation time on the BSA-tryptophan interaction were investigated. This study offers a novel approach for the study of protein-drug interactions.
authors.affiliation: Department of Chemistry, University of Waterloo, Faculty of Science, 200 University Avenue West, Waterloo, Ont., Canada N2L 3G1.
authors.forename: Tao
authors.initials: T
authors.lastname: Bo
authors.forename: Janusz
authors.initials: J
authors.lastname: Pawliszyn
mesh_terms: D000818:Animals; D001665:Binding Sites; D002417:Cattle; D045304:Cytochromes c / Q000737:chemistry; D019075:Electrophoresis, Capillary / Q000379:methods; D007525:Isoelectric Focusing / Q000379:methods*; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013237:Stereoisomerism; D014364:Tryptophan / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D012710:Serum Albumin, Bovine; D014364:Tryptophan; D045304:Cytochromes c