Zhang Chun-Yang, An Cheng-Cai, Wang Rong-Ying, Gong Yi-Xuan, Ma Hui, Chen Die-Yan, Chen Zhang-Liang
National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, China; Molecular and Nano Sciences Laboratory, Department of Physics, Tsinghua University, Beijing 100084, China.
Talanta. 2002 May 24;57(3):467-73.
The type-I ribosome-inactivating protein trichosanthin (TCS) has a broad spectrum of biological and pharmacological activities, including abortifacient, anti-tumor and anti-human-immunodeficiency-virus (anti-HIV). In this study, circular dichroism (CD) and capillary electrophoresis were used for the first time to study TCS and its two TCS mutants of Y55G TCS (tyrosine 55 converted to glycine) and FYY140-142GSA TCS (tripeptide phenylalanine-tyrosine-tyrosine 140-142 converted to glycine-serine-alanine). The results indicated that the substitution of amino acids changed the secondary structures and the hydrophobility of TCS. Moreover, both Y55G TCS and FYY140-142GSA TCS demonstrated attenuated cytotoxicity and reactive oxygen species (ROS) production in human choriocarcinoma cells (JAR cells) as compared to natural TCS and wild-type TCS. Our results demonstrated the cytotoxicity of TCS on JAR cells and TCS-induced production of ROS might be TCS-conformational related, suggesting that CD and capillary electrophoresis study might throw new insight into the anti-tumor and anti-HIV mechanism of TCS.
I型核糖体失活蛋白天花粉蛋白（TCS）具有广泛的生物学和药理活性，包括堕胎、抗肿瘤和抗人类免疫缺陷病毒（抗HIV）。在本研究中，首次使用圆二色性（CD）和毛细管电泳来研究TCS及其两个TCS突变体Y55G TCS（酪氨酸55转换为甘氨酸）和FYY140 - 142GSA TCS（三肽苯丙氨酸 - 酪氨酸 - 酪氨酸140 - 142转换为甘氨酸 - 丝氨酸 - 丙氨酸）。结果表明，氨基酸的取代改变了TCS的二级结构和疏水性。此外，与天然TCS和野生型TCS相比，Y55G TCS和FYY140 - 142GSA TCS在人绒毛膜癌细胞（JAR细胞）中均表现出减弱的细胞毒性和活性氧（ROS）产生。我们的结果证明了TCS对JAR细胞的细胞毒性以及TCS诱导的ROS产生可能与TCS构象有关，这表明CD和毛细管电泳研究可能为TCS的抗肿瘤和抗HIV机制提供新的见解。
