Qu Xue, Komatsu Teruyuki, Sato Takaaki, Glatter Otto, Horinouchi Hirohisa, Kobayashi Koichi, Tsuchida Eishun
Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.
Bioconjug Chem. 2008 Aug;19(8):1556-60. doi: 10.1021/bc800207j. Epub 2008 Jul 22.
We present structure, photoexcited triplet-state property, and singlet oxygen ((1)O 2) generation capability of human serum albumin complexed with a tris(dicarboxymethylene)[60]fullerene C3-isomer (HSA-CF). Small angle X-ray scattering measurements showed that a globular size-dimension and surface charge distribution of HSA were unaltered by monomolecular complexation of CF into the hydrophobic cavity. Laser flash photolysis to the HSA-CF solution yielded a photoexcited triplet state of the CF chromophore ((3)CF*) with lifetime of 46 mus. In the presence of O2, energy transfer occurred from HSA-(3)CF* to O2 to generate (1)O2; the quenching rate constant [k q(O2)] was determined to be 2.2 x 10 (8) M (-1) s (-1). The HSA-CF showed strong photoresistence relative to HSA complexed with a protoporphyrin IX. The quantum yield of (1)O2 production for this artificial protein was compared to those of other photosensitizing agent. The HSA-CF did not show a dark cytotoxicity, but induced cell death efficiently under visible light irradiation.
我们展示了与三（二羧甲基）[60]富勒烯C3异构体（HSA-CF）复合的人血清白蛋白的结构、光激发三重态性质和单线态氧（（1）O2）生成能力。小角X射线散射测量表明，CF单分子络合到疏水腔中不会改变HSA的球状尺寸和表面电荷分布。对HSA-CF溶液进行激光闪光光解，产生了CF发色团的光激发三重态（（3）CF*），寿命为46微秒。在O2存在下，能量从HSA-（3）CF*转移到O2以生成（1）O2；猝灭速率常数[kq（O2）]被确定为2.2×10（8）M（-1）s（-1）。相对于与原卟啉IX复合的HSA，HSA-CF表现出很强的光抗性。将这种人工蛋白质的（1）O2产生量子产率与其他光敏剂的量子产率进行了比较。HSA-CF没有表现出暗细胞毒性，但在可见光照射下能有效地诱导细胞死亡。
