Temperature and cholesterol composition-dependent behavior of 1-myristoyl-2-[12-[(5-dimethylamino-1-naphthalenesulfonyl)amino]dodecanoyl]-sn-glycero-3-phosphocholine in 1,2-dimyristoyl-sn-glycero-3-phosphocholine membranes
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- 作者：Troup ; Gregory M. ; Wrenn ; Steven P.
- 关键词：DANSYL ; 1-myristoyl-2-[12-[(5-dimethylamino-1-naphthalenesulfonyl)amino]dodecanoyl]-sn-glycero-3-phosphocholine ; DMPC ; 1 ; 2-dimyristoyl-sn-glycero-3-phosphocholine ; 5-DOXYL-PC ; 1-palmitoyl-2-stearoyl(5-DOXYL)-sn-glycero-3-phosphocholine ; 16-DOXYL-PC ; 1-pal
- 刊名：Chemistry and Physics of Lipids
- 出版年：2004
- 出版时间：September, 2004
- 年：2004
- 卷：131
- 期：2
- 页码：167-182
- 全文大小：287 K
文摘
We present a steady-state and time-resolved fluorescence emission spectra analysis of the membrane probe 1-myristoyl-2-[12-[(5-dimethylamino-1-naphthalenesulfonyl)amino]dodecanoyl]-sn-glycero-3-phosphocholine (DANSYL) in 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and cholesterol multi-lamellar vesicles (MLV) prepared by modified rapid solvent exchange. We report that the dose-dependent cholesterol-induced blue shifts in the steady-state fluorescence emission spectra observed in DMPC MLV are due to complex solvent effects that include time-dependent dipolar relaxation and the formation of internal charge transfer (ICT) states. A key finding of this investigation is identification of two distinguishable DANSYL populations existing at both shallow and deep locations in the membrane; these two DANSYL populations are evidence of laterally phase-separated domains at cholesterol compositions between Xchol = 0.30 and 0.60 at 30°C in DMPC MLV.