Matayoshi E D, Kleinfeld A M
Biochim Biophys Acta. 1981 Jun 22;644(2):233-43. doi: 10.1016/0005-2736(81)90380-1.
We have measured the fluorescence decay of N-phenyl-1-naphthylamine using the phase-modulation method, in several solvent systems and egg phosphatidylcholine vesicles. The decay is monoexponential in pure solvents (both polar and non-polar) of low viscosity. In polar viscous solvents or in non-polar solvents containing an added polar solute, the decay is heterogeneous and emission wavelength dependent. In such cases, dielectric relaxation and/or excited-rate complexing give rise to a shift of the emission spectrum on the nanosecond time scale. Emission-wavelength-dependent decay was also observed when N-phenyl-1-naphthylamine was bound to egg phosphatidylcholine vesicles. From these results as well as the position of the emission spectral maximum, we conclude that N-phenyl-1-naphthylamine probes the ester-carbonyl region of the phospholipid acyl chains, where it undergoes an excited-state reaction. This result contradicts the often made assumption that N-phenyl-1-naphthylamine probes the deeper hydrocarbon region of the bilayer.
我们使用相位调制法，在几种溶剂体系和卵磷脂酰胆碱囊泡中测量了N-苯基-1-萘胺的荧光衰减。在低粘度的纯溶剂（极性和非极性）中，衰减是单指数的。在极性粘性溶剂或含有添加极性溶质的非极性溶剂中，衰减是不均匀的且与发射波长有关。在这种情况下，介电弛豫和/或激发速率络合会在纳秒时间尺度上导致发射光谱的移动。当N-苯基-1-萘胺与卵磷脂酰胆碱囊泡结合时，也观察到了发射波长依赖性衰减。根据这些结果以及发射光谱最大值的位置，我们得出结论，N-苯基-1-萘胺探测磷脂酰基链的酯羰基区域，在那里它会发生激发态反应。这一结果与通常的假设相矛盾，即N-苯基-1-萘胺探测双层更深的烃区域。
