Kalyanaraman B, Feix J B, Sieber F, Thomas J P, Girotti A W
Proc Natl Acad Sci U S A. 1987 May;84(9):2999-3003. doi: 10.1073/pnas.84.9.2999.
The photochemistry of merocyanine 540 (MC 540), a sensitizing dye that binds preferentially to leukemia and electrically excitable cells, has been investigated. MC 540-mediated photooxidation of histidine, arachidonate, and unsaturated phospholipid vesicles was assessed by spin label oximetry and shown to involve type II (singlet oxygen) chemistry. The dye was also shown to be a potent sensitizer of lipid peroxidation in a natural cell membrane, the erythrocyte ghost. Inhibition by azide, stimulation by 2H2O, and identification of the cholesterol product 5 alpha-cholest-6-ene-3 beta,5-diol in this system, all were consistent with singlet oxygen intermediacy. Finally, MC 540 was found to be considerably more phototoxic to K-562 leukemia cells in 2H2O than in H2O. We conclude that singlet oxygen plays a major role in the phototherapeutic effects of this dye.
部花青540（MC 540）是一种优先与白血病细胞和电可兴奋细胞结合的敏化染料，其光化学性质已得到研究。通过自旋标记血氧测定法评估了MC 540介导的组氨酸、花生四烯酸和不饱和磷脂囊泡的光氧化作用，结果表明其涉及II型（单线态氧）化学反应。该染料还被证明是天然细胞膜（红细胞血影）中脂质过氧化的有效敏化剂。在该系统中，叠氮化物的抑制作用、2H2O的刺激作用以及胆固醇产物5α-胆甾-6-烯-3β,5-二醇的鉴定，均与单线态氧中间体一致。最后，发现MC 540在2H2O中对K-562白血病细胞的光毒性比在H2O中要大得多。我们得出结论，单线态氧在这种染料的光治疗作用中起主要作用。
