多变鱼腥藻藻胆蛋白共价复合物的合成及其分子内能量传递

利用双功能基偶联剂3-(2-吡啶联巯基)丙酸N-羟基琥珀酰亚胺酯(SPDP)合成了两个藻胆蛋白复合物,藻红蓝蛋白-变藻蓝蛋白复合物PEC-APC和藻红蓝蛋白-藻蓝蛋白复合物PEC-PC.利用吸收光谱和荧光光谱证明了藻胆蛋白构型与构象在反应后得到保持。通过荧光光谱观察到能量传递现象。计算出复合物PEC-APC的分子内能量传递效率约为90%.复合物PEC-PC中藻红蓝蛋白PEC的荧光寿命比PEC本身的寿命大大缩短,证明存在分子内能量传递。二硫苏糖醇(DTT)还原二硫桥键后能量传递被阻断。这进一步证明复合物合成成功及分子内能量传递。

THE SYNTHESIS OF CONJUGATES OF PHYCOBILI PROTEINS FROM A. VARIABILIS AND THEIR INTRAMOLECULAR ENERGY TRANSFER PHENOMENA

Two phycobiliprotein conjugates PEC-APC and PEC-PC were synthesized by a heterobifunctional coupling reagent, N-sccinimidly 3-(2-pyridyldithio) propionate. The phycobiliproteins are linked by disulfide bond. The absorption and fluorescence spectra indicate that the constructure and the conformation of the biliproteins were maintained after reaction.The energy transfer phenomenon was observed from fluorescence spectra. The energy transfer efficiency from PEC to APC calculated from the fluorescence spectra is about 90%.The excited state life time of PEC emission in conjugate PEC PC was 0.86 ns, compared with 2.1 ns for free PEC, which indicated that energy transfer did occur from PEC to C-PC in conjugate PEC-PC. The energy transfer was stopped by the addition of dithiothreitol (DTT) to the solutions of the conjugates. These results further confirmed that there was energy transfer in the conjugates.