Interaction between fluoroquinolones and bovine serum albumin studied by affinity capillary electrophoresis.

Liu, Shiwang; Zhang, Li-Wei; Zhang, Xin-Xiang

The interactions between eight fluoroquinolone antibiotics (ciprofloxacin, enoxacin, fleroxacin, levofloxacin, lomefloxacin, norfloxacin, ofloxacin, pefloxacin) and bovine serum albumin (BSA) were studied by affinity capillary electrophoresis (ACE). The binding constants were estimated by the change of migration times of the analytes through the change of concentration of BSA in the buffer solution. The yield binding constants were between 3.19 x 10(4) and 1.21 x 10(5) M(-1). These were related with the structures of fluoroquinolones, and agreed with the results obtained by other techniques. The obtained binding constants may help us in gaining some insights on possible drug/protein interactions and in early evaluation of the drugs' pharmacokinetic profiles during drug discovery.