Rottenberg H
Department of Pathology, Hahnemann University, Philadelphia, Pennsylvania 19102.
Biochemistry. 1992 Oct 6;31(39):9473-81. doi: 10.1021/bi00154a021.
Prodan [6-propionyl-2-(dimethylamine)naphthalene] is a hydrophobic fluorescent probe which is extremely sensitive to both the polarity and the hydrogen-bond donating capacity of the solvent. In binary mixtures of solvents, the hydrogen-bond donating effect on Prodan fluorescence saturates at relatively low concentrations of protic solvent while the polarity effect is proportional to the mixture's dielectric constant. The fluorescence emission maximum is approximately a linear function of the dielectric constant in both protic and aprotic solvents, and this allows estimation of the dielectric constant in both environments. In phospholipid bilayers and biological membranes, Prodan exhibits two distinct emission peaks: blue (430-445 nm) and green (470-505 nm). Temperature determines the relative intensity of the two peaks, but their wavelengths depend on the type of membrane and appear to reflect a specific membrane environment. In phospholipid vesicles, alcohols reduce the fluorescence intensity of the blue peak and produce a red-shift in the emission maximum of the green peak. Taking the partition coefficients of the alcohols into account, short-chain alcohols are much more effective than longer-chain alcohols in red-shifting the emission maximum of the green peak. Alcohols have similar effects on Prodan fluorescence in liver microsomal and mitochondrial membranes, synaptosomal membranes, and red blood cell plasma membranes. However, in liver organelle membranes the red-shift of the green peak is the dominant effect while in plasma membranes the quenching of the fluorescence of the blue peak is dominant. These effects are observed at low (pharmacological) ethanol concentrations and provide a unique tool for probing the interactions of ethanol with biological membranes.(ABSTRACT TRUNCATED AT 250 WORDS)
Prodan（6-丙酰基-2-（二甲胺）萘）是一种疏水性荧光探针，对溶剂的极性和氢键供体能力都极为敏感。在二元溶剂混合物中，质子溶剂对Prodan荧光的氢键供体效应在相对较低浓度时就会饱和，而极性效应与混合物的介电常数成正比。在质子溶剂和非质子溶剂中，荧光发射最大值大致是介电常数的线性函数，这使得在两种环境下都能估算介电常数。在磷脂双层和生物膜中，Prodan呈现出两个不同的发射峰：蓝色（430 - 445纳米）和绿色（470 - 505纳米）。温度决定了两个峰的相对强度，但其波长取决于膜的类型，似乎反映了特定的膜环境。在磷脂囊泡中，醇类会降低蓝色峰的荧光强度，并使绿色峰的发射最大值发生红移。考虑到醇类的分配系数，短链醇在使绿色峰的发射最大值红移方面比长链醇更有效。醇类对肝脏微粒体和线粒体膜、突触体膜以及红细胞质膜中的Prodan荧光有类似影响。然而，在肝脏细胞器膜中，绿色峰的红移是主要效应，而在质膜中，蓝色峰荧光的猝灭是主要效应。这些效应在低（药理）乙醇浓度下就能观察到，为探究乙醇与生物膜的相互作用提供了一种独特的工具。（摘要截短至250字）
