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Comparative Investigation on the Interaction of Cefonicid Sodium with Bovine Transferrin and Bovine Serum Albumin by Multi-Spectroscopy

Duan S, Liu B, Li T and Cui M

The reaction mechanisms of cefonicid sodium to bovine serum albumin and bovine transferrin were studied by multi-spectroscopy methods. The results demonstrated that new complexes were formed between cefonicid sodium and the two proteins, which resulted in a static quenching of fluorescence of the two proteins. And the numbers of binding sites in the two systems were approximately equal to 1. In the reaction system, the drug binds with the two proteins mainly through electrostatic force. It also showed that in the two systems the hydrophobic environment around amino acid residues changed, and the primary binding sites for cefonicid sodium were both closer to tryptophan residues. Circular dichroism spectroscopy showed that the secondary structures of the two proteins were changed. The values of Hill's coefficients indicating that there were negative co-operativities in the interaction between subsequent ligands and the two proteins. In addition, the studies have showed that the binding between bovine serum albumin and cefonicid sodium was stronger. However, cefonicid sodium had larger influences on the microenvironment of bovine transferrin. The interaction between cefonicid sodium and different proteins will be helpful for extracting the common features, applying the unique characteristic of drug-proteins systems.