Title
Probing the interaction of cephalosporin with bovine serum albumin: A structural and comparative perspective
Author
Li-Yang Cheng, Cheng-Zhang Yang, Hui-Zi Li, Min Li, Ai-Min Bai, Yu Ouyang, Yan-Jun Hu
Year
2017
Journal
Luminescence
Abstract
Cephalosporins belong the largest class of antibiotics used in the treatment of a wide range of infectious diseases caused by susceptible organisms. In the present study, we chose two typical antibiotics cefalexin/cefixime based on their structure, and investigated the interaction of cephalexin/cefixime with bovine serum albumin (BSA) using UV–vis absorption spectra, fluorescence spectroscopy, circular dichroism (CD) spectroscopy and molecular modeling approaches. Spectroscopic experiments revealed the formation of a BSA − cefalexin/cefixime complex. The binding parameters calculated using a modified Stern − Volmer method and the Scatchard method reached 103–104 L·mol−1. Thermodynamic parameter studies revealed that binding characteristics by negative enthalpy and positive entropy changes, and electrostatic interactions play a major role. Site marker competitive displacement experiments and molecular modeling approaches demonstrated that cefalexin and cefixime bind with appropriate affinity to site I (subdomain IIA) of BSA. Furthermore, synchronous fluorescence spectra, CD spectra and molecular modeling results indicated that the secondary structure of BSA was changed in the presence of cefalexin and cefixime. Additionally, the effects of metal ions on the BSA − cefalexin/cefixime system were also assessed.
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Ligand binding, Protein folding, Biochemistry