Photobleaching of a cyanine dye in solution and in membranes.
Photobleaching of a cyanine dye in solution and in membranes.
复制标题
花青染料在溶液和膜中的光漂白。
DOI：
10.1111/j.1751-1097.1987.tb05384.x
复制
发表时间：
1987
影响因子：
3.3
通讯作者：
Kochevar,IE
中科院分区：
文献类型：
--
作者：
Valdes-Aguilera,O;Cincotta,L;Foley,J;Kochevar,IE
N，N′-双（2-乙基-1，3-二氧戊环）-Kryptocyanine（EDKC）是一种具有离域正电荷的亲脂性染料，可使细胞对可见光照射光敏化。在磷酸盐缓冲液（PBS）中，EDKC在700 nm（ε= 1.2 × 105 M −1cm−1）处吸收最大，在甲醇中，EDKC在706 nm（ε= 2.3 × 105 M −1cm−1）处吸收最大。EDKC从PBS中分配到由饱和磷脂制备的小单层脂质体和由红细胞（RBC）制备的膜中，并与人血清白蛋白（HSA）结合。EDKC荧光最大值从PBS中的713 nm红移到脂质体和RBC膜中的720-725 nm，并且与PBS相比，荧光强度增强14-35倍（φ= 0.0046）。EDKC在PBS中是热不稳定的（T1/2= 2 h，1.3 × 10− 5 MEDKC），但在甲醇中是稳定的。在脂质体和RBC膜中，EDKC比在PBS中稳定10倍，表明它仅部分暴露于水相。脂质体和红细胞膜中EDKC荧光被三硝基苯磺酸盐淬灭也表明EDKC没有被埋在膜内。EDKC的光分解是氧依赖性的，并且以低量子产率（6.4 × 10− 4在PBS中）发生。在膜中或用HSA照射EDKC时未检测到单线态氧，因为EDKC的自敏化氧化在D2 O中与在H2O中以相同的速率发生，并且未被叠氮化钠或组氨酸淬灭。
N,N′‐bis(2‐ethyl‐1,3‐dioxolane)‐kryptocyanine (EDKC), a lipophilic dye with a delocalized positive charge, photosensitizes cells to visible irradiation. In phosphate‐buffered saline (PBS), EDKC absorbs maximally at 700 nm (ε= 1.2 × 105M−1cm−1) and in methanol, the absorption maximum is at 706 nm (ε= 2.3 × 105M−1cm−1). EDKC partitions from PBS into small unilamellar liposomes prepared from saturated phospholipids and into membranes prepared from red blood cells (RBC) and binds to human serum albumin (HSA). The EDKC fluorescence maximum red shifts from 713 nm in PBS to 720–725 nm in liposomes and RBC membranes and the fluorescence intensity is enhanced by factors of 14–35 compared to PBS (φ= 0.0046). EDKC is thermally unstable in PBS (T1/2= 2 h at 1.3 × 10−5MEDKC), but stable in methanol. In liposomes and RBC membranes, EDKC is 10 times more stable than in PBS, indicating that it is only partially exposed to the aqueous phase. Quenching of EDKC fluorescence in liposomes and RBC membranes by trinitrobenzene sulfonate also indicates that EDKC is not buried within the membranes. Photodecomposition of EDKC was oxygen‐dependent and occurred with a low quantum yield (6.4 × 10−4in PBS). Singlet oxygen was not detected upon irradiation of EDKC in membranes or with HSA since the self‐sensitized oxidation of EDKC occurred at the same rate in D2O as in H2O and was not quenched by sodium azide or histidine.