Effect of CdTe QDs on the protein-drug interactions

Abstract

Recently, investigations of biological toxicity of cadmium QDs and their toxic interaction with plasma proteins have attracted great interest. In this work, flavonoids were studied for the affinities for human serum albumin (HSA) in the presence and absence of CdTe G-QDs by fluorescence quenching method. CdTe G-QDs obviously enhanced the binding affinities of kaempferol, genistein and biochanin A by 3.78 to 154.88 times depending on the QDs concentration. However, the affinity of kaempferide for HSA was slightly weakened in the presence of G-QDs. The non-methylated flavonoids were more sensitive to G-QDs than their methylated forms. The affinities of kaempferide and kaempferol for HSA at first were slightly improved and then obviously decreased with increasing G-QDs concentration. For genistein, the affinities for HSA decreased with increasing G-QDs concentration. However, the G-QDs concentration showed no obvious effect on the affinity of biochanin A. The binding affinities of flavonoids for HSA improved with increasing QDs size.

Keywords::

• CdTe QDs
• protein-drug interactions
• flavonoids
• fluorescence quenching
• affinity

Acknowledgements

The authors thank Dr Xinlin Wei, Dr. Yuanfeng Wang and Mir Yalong Bai for preparing CdTeQDs.

Declaration of interest: The authors are grateful for financial sponsored by Shanghai Rising-Star Program (11QA1404700), Natural Science Foundation of Shanghai (10ZR1421700), Leading Academic Discipline Project of Shanghai Municipal Education Commission (J50401), “Chen Guang” project supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation (09CG46), Innovation Program of Shanghai Municipal EducationCommission (10YZ68), Program of Shanghai Normal University (SK201006), National Transgenic Organism New Variety Culture Key Project (2009ZX08012-002B), National Natural Science Fund (30900110), Project from Ministry of Science and Technology of China (NC2010AE0075,NC2010AE0372), and Shanghai Science and Technology Committee Project (10JC1412000, 09QH1401900, 08391911800). The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.