Interaction of an Antituberculosis Drug with a Nanoscopic Macromolecular Assembly: Temperature-Dependent Fo虉rster Resonance Energy Transfer Studies on Rifampicin in an Anionic Sodium Dodecyl Sulfate M
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- 作者：Tanumoy Mondol ; Priya Rajdev ; Abhinandan Makhal ; Samir Kumar Pal
- 刊名：Journal of Physical Chemistry B
- 出版年：2011
- 出版时间：March 31, 2011
- 年：2011
- 卷：115
- 期：12
- 页码：2924-2930
- 全文大小：1012K
- 年卷期：v.115,no.12(March 31, 2011)
- ISSN：1520-5207
文摘
In this contribution, we report studies on the nature of binding of a potent antituberculosis drug, Rifampicin (RF) with a model drug delivery system, sodium dodecyl sulfate (SDS) micelle. Temperature dependent dynamic light scattering (DLS), conductometry, and circular dichroism (CD) spectroscopy have been employed to study the binding interaction of the drug with the micelle. The absorption spectrum of the drug RF in the visible region has been employed to study F枚rster resonance energy transfer (FRET) from another fluorescent drug Hoechst 33258 (H33258), bound to the micelle. Picosecond-resolved FRET studies at room temperature confirm the simultaneous binding of the two drugs to the micelle and the distance between the donor鈭抋cceptor pair is found to be 34 脜. The temperature dependent FRET study also confirms that the location and efficiency of drug binding to the micelle changes significantly at the elevated temperature. The energy transfer efficiency of the donor H33258, as measured from time-resolved studies, decreases significantly from 76% at 20 掳C to 60% at 55 掳C. This reveals detachment of some amount of the drug molecules from the micelles and increased donor鈭抋cceptor distance at elevated temperatures. The estimated donor鈭抋cceptor distance increases from a value of 33 脜 at 20 掳C to 37 脜 at 55 掳C. The picosecond resolved FRET studies on a synthesized DNA bound H33258 in RF solution have been performed to explore the interaction between the two. Our studies are expected to find relevance in the exploration of a potential vehicle for the vital drug rifampicin.