Wang Jian Hua, Nie Hui Ling, Tam Siu Cheung, Huang Hai, Zheng Yong Tang
Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, PR China.
FEBS Lett. 2002 Nov 6;531(2):295-8. doi: 10.1016/s0014-5793(02)03539-1.
Trichosanthin (TCS) is a type I ribosome inactivating (RI) protein possessing anti-tumor and antiviral activity, including human immunodeficiency virus (HIV). The mechanism of these actions is not entirely clear, but is generally attributed to its RI property. In order to study the relationship between the anti-HIV-1 activity of TCS and its RI activity, three TCS mutants with different RI activities were constructed by using site-directed mutagenesis. The anti-HIV-1 activities of the three mutants were tested in vitro. Results showed that two TCS mutants, namely TCS(M(120-123)), TCS(E160A/E189A), with the greatest decrease in RI activity, lost almost all of the anti-HIV activity and cytopathic effect. Another mutant TCS(R122G), which exhibited a 160-fold decrease in RI activity, retained some anti-HIV activity. The results from this study suggested that RI activity of TCS may have significant contribution to its anti-HIV-1 property.
天花粉蛋白（TCS）是一种I型核糖体失活（RI）蛋白，具有抗肿瘤和抗病毒活性，包括对人类免疫缺陷病毒（HIV）。这些作用的机制尚不完全清楚，但一般归因于其RI特性。为了研究TCS的抗HIV-1活性与其RI活性之间的关系，利用定点诱变构建了三种具有不同RI活性的TCS突变体。在体外测试了这三种突变体的抗HIV-1活性。结果表明，两种RI活性下降最大的TCS突变体，即TCS(M(120-123))、TCS(E160A/E189A)，几乎丧失了所有的抗HIV活性和细胞病变效应。另一个突变体TCS(R122G)，其RI活性下降了160倍，仍保留了一些抗HIV活性。该研究结果表明，TCS的RI活性可能对其抗HIV-1特性有显著贡献。
