Study on the Interaction of Bovine Serum Albumin with Ceftriaxone and the Inhibition Effect of Zinc (II)

Qiaoli Yue,Tongfei Shen,Jifeng Liu,Chaohui Gao,Changna Wang

doi:10.1155/2012/284173

Abstract

The mechanism of the interaction between bovine serum albumin (BSA) and ceftriaxone with and without zinc (II) (Zn2+) was studied employing fluorescence, ultraviolet (UV) absorption, circular dichroism (CD), and synchronous fluorescence spectral methods. The intrinsic fluorescence of BSA was quenched by ceftriaxone in a static quenching mode, which was authenticated by Stern-Volmer calculations. The binding constant, the number of binding sites, and the thermodynamic parameters were obtained, which indicated a spontaneous and hydrophobic interaction between BSA and ceftriaxone regardless of Zn2+. Changes in UV absorption, CD, and synchronous fluorescence spectral data are due to the microenvironment of amide moieties in BSA molecules. In the BSA-ceftriaxone-Zn2+system, Zn2+must first interact with ceftriaxone forming a complex, which inhibits BSA binding to ceftriaxone. The present work uses spectroscopy to elucidate the mechanism behind the interaction between BSA and ceftriaxone in the presence and absence of Zn2+. The BSA and ceftriaxone complex provides a model for studying drug-protein interactions and thus may further facilitate the study of drug metabolism and transportation.

Highlights

The interaction between biomacromolecules, especially between plasma proteins and drugs, has been an interesting research field in life sciences, chemistry, and clinical medicine [1]
Drug-albumin complexes may be considered as models for gaining fundamental insights into drug-protein interactions
Albumins are characterized by a low content of tryptophan and methionine and a high content of cystine and charged amino acids [3,4,5]

Summary

Introduction

The interaction between biomacromolecules, especially between plasma proteins and drugs, has been an interesting research field in life sciences, chemistry, and clinical medicine [1]. Albumins are characterized by a low content of tryptophan and methionine and a high content of cystine and charged amino acids [3,4,5]. Brown elucidated the 607 amino acid residue, primary structure of BSA in 1975, twenty one of which are tyrosine (Tyr) residues and two of which are tryptophan (Trp) residues located at positions 134 and 212, respectively [3, 6]. These two Trp residues cause BSA to have intrinsic fluorescence

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