Key Laboratory of Chemistry in Ethnic Medicinal Resources, State Ethnic Affairs Commission & Ministry of Education, Yunnan Minzu University, Kunming 650500, China.
TELI College, Beijing Institute of Technology, Beijing 100081, China.
Toxins (Basel). 2024 Oct 13;16(10):440. doi: 10.3390/toxins16100440.
Malanin is a new type II ribosome-inactivating protein (RIP) purified from , a rare, endangered tree is only found in the southwest of Guangxi Province and the southeast of Yunnan Province, China. The gene coding sequence of malanin was found from the cDNA library of seeds by employing the ten N-terminal amino acid sequences of malanin, DYPKLTFTTS for chain-A and DETXTDEEFN (X was commonly C) for chain-B. The results showed a 65% amino acid sequence homology between malanin and ricin by DNAMAN 9.0 software, the active sites of the two proteins were consistent, and the four disulfide bonds were in the same positions. The primary sequence and three-dimensional structures of malanin and ricin are likely to be very similar. Our studies suggest that the mechanism of action of malanin is expected to be analogous to ricin, indicating that it is a member of the type II ribosome-inactivating proteins. This result lays the foundation for further study of the anti-tumor activities of malanin, and for the application of malanin as a therapeutic agent against cancers.
马拉宁是从中国广西西南部和云南东南部特有的珍稀濒危树种石山桂花种子中分离得到的一种新型 II 型核糖体失活蛋白（RIP）。通过采用马拉宁的 10 个 N 端氨基酸序列 DYPKLTFTTS（链 A）和 DETXTDEEFN（X 通常为 C）（链 B），从石山桂花种子 cDNA 文库中找到了马拉宁的基因编码序列。DNAMAN 9.0 软件分析结果表明，马拉宁与蓖麻毒素的氨基酸序列同源性为 65%，两种蛋白的活性位点一致，四个二硫键的位置相同。马拉宁和蓖麻毒素的一级序列和三维结构可能非常相似。我们的研究表明，马拉宁的作用机制预计类似于蓖麻毒素，表明它是 II 型核糖体失活蛋白家族的成员。这一结果为进一步研究马拉宁的抗肿瘤活性以及将马拉宁作为抗癌治疗剂的应用奠定了基础。
