On The Interaction Between Drugs And Bovine Serum Albumin By Fluorescence Spectroscopy

Serum albumin, as one of the most abundant carrier proteins, plays an important role in the transport and disposition of endogenous and exogen- -ous ligands present in blood. Distribution and metabolism of many biol- -ogically active compounds,such as metabolites, drugs and other organic compounds in the body,are correlated with their affinities towards serum albumin. Consequently, bovine serum albumin (BSA) is selected as a drug targeting to study the interaction and oxidative damage effect because of its low cost, ready availability and the results of all the studies are consistent with the fact that BSA and human serum albumins (HSAs) are homologous proteins.Flavonoids are an interesting group of natural polyphenolic compounds that exhibit extensive bioactivities such as scavenging free radical, antitu- -mor and antiproliferative effects. The anticancer and antiviral effects of these natural products are attributed to their potential biomedical applica- -tions. Some western medicines, such as metcycline, have extensive great clinical applications. In this study, the drugs of flavonoid and tetracycline were selected as targets to interact with BSA.The interaction mechanisms of Isorhamnetin(ISO)and bovine serum albumin (BSA), ISO and several metal ions were studied using ultraviolet-visible absorption spectrum and fluorescence spectroscopy. BSA and the compounds of the interactions of ISO and several metal ions were also studied. These experimental results show that the static gravitation is the major force of the combination about the interaction of ISO and bovine BSA. Flourescence of BSA is quenched by ISO with the static mechanism. The binding styles of several metal ions and ISO were studied, too. It shows the binding mechanisms of some complexes of metal ions and ISO with BSA. It indicates that the interventions of metal ions affect the combination of ISO and BSA, they depress their abilities of combination.Likewise, the interactions of metcycline (METC) and bovine serum al- -bumin (BSA) were studied by fluorescence spectrometry and UV-Visible absorption spectrometry in this paper. The effects of temperatures, pH, m- -etal ions on the interactions of METC and BSA were studied. The results indicate that the mechanisms of the interactions of METC with BSA belo- -ng to static quenching. The major force of binding is static gravitation.Also, the distance of METC-BSA was calculated by F?rster theory of non -radiation energy transfer. The mechanisms of interactions of metal com- -plexes with BSA also belong to static quenching. The binding constants are different to the constant of the interaction between METC and BSA at room temperature, and the relevant binding sites are changed. It shows that the metal ions affect the structure and hydrophobicity of METC.