Gross E, Ehrenberg B
Department of Physics, Bar Ilan University, Ramat Gan, Israel.
Biochim Biophys Acta. 1989 Jul 24;983(1):118-22. doi: 10.1016/0005-2736(89)90388-x.
Spectroscopic techniques were employed to establish the first comparative evaluation of the partition of the photosensitizers hematoporphyrin derivative (HPD) and photofrin II (PF-II) into phosphatidylcholine (PC) and PC/cholesterol liposomes. The fluorescence of the dyes was monitored while they were titrated with liposomes, yielding the dyes' effective binding constants to the membranes. The binding constants of HPD and PF-II to PC liposomes are 12.2 +/- 0.3 (mg/ml)-1 and 9.2 +/- 0.8 (mg/ml)-1 and to PC/cholesterol (50% w/w) liposomes they are 6.7 +/- 0.9 (mg/ml)-1 and 8.0 +/- 0.8 (mg/ml)-1, respectively. The vertical distribution of the dyes in the bilayer was determined by quenching their fluorescence with spin-labeled stearic acids. PF-II was found to reside deeper in the membrane than HPD. Cholesterol was found to modulate the distribution of the two dyes to a greater extent then DPPC and DMPC. The modulation mechanism is discussed.
采用光谱技术首次对光敏剂血卟啉衍生物（HPD）和光卟啉II（PF-II）在磷脂酰胆碱（PC）和PC/胆固醇脂质体中的分配进行了比较评估。在用脂质体滴定染料时监测其荧光，得出染料与膜的有效结合常数。HPD和PF-II与PC脂质体的结合常数分别为12.2±0.3（mg/ml）-1和9.2±0.8（mg/ml）-1，与PC/胆固醇（50%w/w）脂质体的结合常数分别为6.7±0.9（mg/ml）-1和8.0±0.8（mg/ml）-1。通过用自旋标记硬脂酸淬灭染料荧光来确定染料在双层膜中的垂直分布。发现PF-II比HPD更深入地存在于膜中。发现胆固醇比二棕榈酰磷脂酰胆碱（DPPC）和二肉豆蔻酰磷脂酰胆碱（DMPC）更能调节这两种染料的分布。讨论了调节机制。
