Quenching of the Intrinsic Fluorescence of Human Serum Albumin by Trimethoxyphenylfluorone–Mo(VI) Complex

Abstract

The interaction mechanism between trimethoxyphenylfluorone (TM‐PF)–molybdenum [Mo(VI)] complex and human serum albumin (HSA) has been investigated using fluorescence method. The binding constants were measured at different temperature. Based on the theory of Förster energy transfer, the binding distance and the energy transfer efficiency between TM‐PF–Mo(VI) complex and HSA were obtained. According to the thermodynamic parameters, the main sorts of binding force can be judged. The results indicate that HSA and TM‐PF–Mo(VI) complex have strong interactions. The mechanism of quenching belongs to static quenching, and the main sorts of binding force are van der Waals force and H‐bonding.

Keywords:

• Binding constant
• energy transfer
• fluorescence quenching
• human serum albumin
• trimethoxyphenylfluorone–Mo(VI) complex

Acknowledgments

This study was supported by the Natural Science Foundation of China (no. 50373017), the Natural Science Foundation (Y2004B11), the Science and Technology Program of Shandong Province (03C05), and the Jinan University Doctoral and Key Foundation (B0405), and all the authors express their deep thanks.