Pooler J P
Photochem Photobiol. 1989 Jul;50(1):55-68. doi: 10.1111/j.1751-1097.1989.tb04129.x.
Eosin derivatives that bind primarily to lipid or protein sites in erythrocyte membranes were studied in solution and as sensitizers of erythrocyte membranes. In 50% ethanol-water mixtures eosin maleimide (EYMA) and 5-N-hexadecanoyl amino eosin (E16) had nearly identical absorption spectra. Higher ethanol concentrations did not change peak absorbances. In the presence of neutral detergent both sensitizers had equivalent absorbance at all ethanol concentrations. In water, EYMA was more effective than E16 at bleaching RNO, probably because of E16 aggregation into micelles, while in ethanol-water mixtures E16 was slightly more effective at bleaching DPBF, indicating equivalent singlet oxygen generation when the sensitizers are in monomeric form. In water with neutral detergent, azide in the 20 microM range inhibited the majority of RNO bleaching with both sensitizers; in 50% ethanol-water mixtures azide at 1 mM showed a 50% inhibition of DPBF bleaching with both sensitizers. Iodide in the 30 mM range reduced DPBF bleaching by 50% in 50% ethanol-water mixtures. When matched for amount loaded in erythrocyte membranes these sensitizers were about equally effective at sensitizing induction of cation permeability, assayed as rate of delayed photohemolysis, while E16 was slightly more effective at sensitizing loss of cholinesterase (AchE) activity. The relation of lysis rate to load was somewhat steeper for E16 than EYMA. For both sensitizers lysis rate increased at about the 1.5 power of light dose. Deoxygenation of the reaction media with argon totally blocked detectable photomodification. Ghost membranes made from sensitizer-treated cells were effective generators of singlet oxygen, assayed by RNO bleaching. However, when mixtures of EYMA-treated and untreated cells were illuminated together, only the EYMA-treated cells showed evidence of photomodification. Azide at 5 mM slowed the initial rate of AchE loss by about 75% with E16 and EYMA. Azide partially slowed photohemolysis. Azide decreased RNO bleaching by sensitizer-treated ghosts as it did in water with detergent micelles. A deuterium oxide solvent increased photohemolysis rate with E16 by 41%, but did not increase photohemolysis rate with EYMA. Deuterium oxide had a positive, but statistically insignificant effect on loss of AchE with both sensitizers. Deuterium oxide following illumination slowed lysis sensitized by both sensitizers more than 50%. Iodide exerted a modest inhibition of photohemolysis and loss of AchE sensitized by E16, but had virtually no influence on sensitization by EYMA. The results in solution indicate that EYMA and E16 have nearly identical photochemical properties when in monome
对主要结合红细胞膜脂质或蛋白质位点的曙红衍生物进行了溶液研究以及作为红细胞膜敏化剂的研究。在50%乙醇 - 水混合物中，马来酰亚胺基曙红（EYMA）和5 - N - 十六酰氨基曙红（E16）具有几乎相同的吸收光谱。较高的乙醇浓度不会改变峰值吸光度。在中性去污剂存在下，两种敏化剂在所有乙醇浓度下都具有相同的吸光度。在水中，EYMA在漂白RNO方面比E16更有效，这可能是因为E16聚集成胶束，而在乙醇 - 水混合物中，E16在漂白DPBF方面略有效，表明当敏化剂呈单体形式时产生单线态氧的能力相当。在含有中性去污剂的水中，20 microM范围内的叠氮化物抑制了两种敏化剂对大多数RNO的漂白作用；在50%乙醇 - 水混合物中，1 mM的叠氮化物对两种敏化剂漂白DPBF的作用有50%的抑制。30 mM范围内的碘化物在50%乙醇 - 水混合物中使DPBF漂白减少50%。当在红细胞膜中加载量相匹配时，这些敏化剂在敏化诱导阳离子通透性方面效果大致相同，以延迟光溶血速率测定，而E16在敏化胆碱酯酶（AchE）活性丧失方面略有效。E16的裂解速率与加载量的关系比EYMA更陡峭。对于两种敏化剂，裂解速率大约随光剂量的1.5次方增加。用氩气使反应介质脱氧完全阻断了可检测到的光修饰。由敏化剂处理的细胞制成的血影膜是有效的单线态氧发生器，通过RNO漂白测定。然而，当将EYMA处理的细胞和未处理的细胞混合物一起照射时，只有EYMA处理的细胞显示出光修饰的迹象。5 mM的叠氮化物使E16和EYMA导致的AchE丧失的初始速率减慢约75%。叠氮化物部分减缓了光溶血。叠氮化物使敏化剂处理的血影膜的RNO漂白减少，就像在含有去污剂胶束的水中一样。重水溶剂使E16的光溶血速率增加41%，但未增加EYMA的光溶血速率。重水对两种敏化剂导致的AchE丧失有正向但无统计学意义的影响。照射后的重水使两种敏化剂致敏的裂解减慢超过50%。碘化物对E16致敏的光溶血和AchE丧失有适度抑制作用，但对EYMA致敏几乎没有影响。溶液中的结果表明，EYMA和E16呈单体形式时具有几乎相同的光化学性质
