Bekasova O D, Muslimov I A, Krasnovskiĭ A A
Mol Biol (Mosk). 1984 Jul-Aug;18(4):1121-7.
The ability of phycobilisomes (PBS) to photosensitize the reduction of methylviologen by dithiothreitol has been shown. This reaction has been studied in dependence on the structural integrity of PBS, nature and pH of the medium, and concentration of reagents. The action spectrum of the reaction has been measured, and its quantum yield has been detected. The quenching of PBS fluorescence by methylviologen has been studied. The maximum rate of electron transfer photosensitized by PBS is observed in 0.6 M phosphate buffer containing 30% of glycerine, pH 9.5. The saturation occurs at methylviologen concentration of 2 X 10(-4) M. Under these conditions the PBS activity reaches 0,3 mumol/mg PBS.h and increases 100 times after preliminary heating of the reaction mixture for 5 min. at 35 degrees C. The light in the range of 520-680 nm is active for the photosensitized reduction of methylviologen. The quantum yield of the reaction is about 2%. In structures phycobiliproteins are more effective sensitizers than in solutions. The highest activity is observed for the substructure of PBS which contains allophycocyanin B and allophycocyanin C (34S particle). The possible mechanisms of the reaction are under consideration.
藻胆体（PBS）使二硫苏糖醇将甲基紫精还原进行光敏化的能力已得到证实。该反应已根据PBS的结构完整性、介质的性质和pH值以及试剂浓度进行了研究。已测量了该反应的作用光谱，并检测了其量子产率。研究了甲基紫精对PBS荧光的猝灭作用。在含有30%甘油、pH值为9.5的0.6M磷酸盐缓冲液中观察到PBS光敏化的最大电子转移速率。在甲基紫精浓度为2×10（-4）M时出现饱和。在这些条件下，PBS活性达到0.3μmol/mg PBS·h，在35℃下将反应混合物预加热5分钟后活性增加100倍。520 - 680nm范围内的光对甲基紫精的光敏化还原具有活性。该反应的量子产率约为2%。在结构中，藻胆蛋白比在溶液中是更有效的敏化剂。对于含有别藻蓝蛋白B和别藻蓝蛋白C的PBS亚结构（34S颗粒）观察到最高活性。正在考虑该反应的可能机制。
