摘要
通过杂双官能团偶联试剂，３－（２－吡啶联疏基）丙酸Ｎ－羟基琥珀酰亚胺酯（ＳＰＤ），我们合成了Ｒ－藻红蛋白（Ｒ－ＰＥ）与变藻蓝蛋白（ＡＰＣ）的共轭复合物。这种光动力复合藻胆蛋白具有一些特别的光物理性质，如很大的ｓｔｏｋｅｓ位移（约１７０ｕｍ，４９０ｎｍ激发，６６５ｎｍ发出荧光）、高效的分子内能量传递效率等。复合物中Ｒ—ＰＥ与ＡＰＣ的摩尔比为１４，且Ｒ—ＰＥ和ＡＰＣ在复合物中保持了它们各自的光谱性质。通过荧光发射光谱，我们观察到了这种复合藻胆蛋白的分子内能量传递现象，计算表明从Ｒ—ＰＥ到ＡＰＣ的分子内能量传递效率为６５％。二硫苏糖醇（ＤＴＴ）对复合物中联结Ｒ—ＰＥ与ＡＰＣ间的脂族二硫桥键的还原导致分子内能量传递的阻断这一现象进一步证实了复合物中存在分子内能量传递现象。根据Ｆｏｒｓｔｅｒ能量转移机理，计算得出给体与受体发色团间距离为７２Ａ，这一距离与两种蛋白的大小是基本相符的。
The conjugate of R-phycoerythrin (R-PE) and Allophycocyanin (APC) was synthesized through a heterobifunctional coupling reagent, N-succinmidyl 3-(2-pyridyldithio) Propionate. The photodynamic phycobiliprotein conjugate possessed some distinctive photophysical properties, such as large Stokes shift (about 170um, excited at 490um, emission at 665um) and high efficency of intramolecular energy transfer etc.. The molar ratio of R-PE to APC was 1.4 in the conjugate, and the two proteins of the conjugate maintained themselves sp￣ectroscopic features resembled in natural resembled in natural state. We observed the intramolecular energy transfer in the conjugate throtigh its fluorescence speCtra. The calculated results showed that the effidency of energy transfer from R-PE to APC was 65%. The phenomena of by DTT reduced the aliphatic disulfide bridge between R-PE and APC in the conjugate further verified the intramolecular energy hansfer from R-PE to APC. The distance between donor and amptor calculated by Forster theory agress with the dimensions of R-PE and APC.
出处
《生物物理学报》
CAS
CSCD
北大核心
1995年第3期439-445,共7页
Acta Biophysica Sinica
基金
自然科学基金
关键词
藻类
藻胆蛋白
蛋白复合物
分子内能量传递
Phycobiliproteins Protein conjugate Intramolecular energy transfer Biological fluorescent techniques
