The Interaction of Cefoperazone Sodium with Bovine Transferrin and Bovine Serum Albumin

The interactions of cefoperazone sodium with bovine transferrin and bovine serum albumin were studied by multi-spectroscopic methods. Results showed that the intrinsic fluorescence of proteins was quenched by the cefoperazone sodium with a static quenching procedure. The thermodynamics parameters indicated that electrostatic attraction played a major role in the interactions of drug and proteins. The results of synchronous fluorescence spectra demonstrated that the microenvironments of amino acid residues of the two proteins were disturbed by cefoperazone sodium and the binding site of cefoperazone sodium to the bovine transferrin/bovine serum albumin was closer to tryptophan residues. Circular dichroism indicated that cefoperazone sodium changed the secondary structures of the two proteins. Hill’s coefficient showed that there was negative cooperation in the interaction of subsequent cefoperazone sodium with bovine transferrin/bovine serum albumin. Moreover, the results showed that cefoperazone sodium bound to bovine serum albumin with higher affinity. However, cefoperazone sodium had larger influences on the microenvironment of bovine transferrin. The interaction between cefoperazone sodium and different proteins will be helpful for extracting the common features, applying the unique characteristic of drug-proteins systems.