title: Study of the interactions between fluoroquinolones and human serum albumin by affinity capillary electrophoresis and fluorescence method.
abstract: The interactions between fluoroquinolones and human serum albumin (HSA) were investigated by affinity capillary electrophoresis (ACE) and fluorescence quenching technique. Based on the efficient separation of several fluoroquinolones using a simple phosphate buffer, the binding constants of fluoroquinolones with HSA were determined simultaneously during one set of electrophoresis by ACE method. The thermodynamic parameters were obtained from data at different temperatures, and the negative deltaH and deltaS values showed that both hydrogen bonds and van der Waals interaction played major roles in the binding of fluoroquinolones to HSA. The interactions were also studied by fluorescence quenching technique. The results of fluorescence titration revealed that fluoroquinolones had the strong ability to quenching the intrinsic fluorescence of HSA through the static quenching procedure. The binding site number n, apparent binding constant K(b) and the Stern-Volmer quenching constant K(sv) were determined. The thermodynamic parameters were also studied by fluorescence method, and the results were consonant with that of ACE.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, College of Chemistry, Peking University, Beijing 100871, China.
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Zhang
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
authors.forename: Xin-Xiang
authors.initials: XX
authors.lastname: Zhang
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002138:Calibration; D002846:Chromatography, Affinity; D019075:Electrophoresis, Capillary; D024841:Fluoroquinolones / Q000737:chemistry*; D006801:Humans; D011485:Protein Binding; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012709:Serum Albumin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D012709:Serum Albumin