Characterization of two linear cationic antimalarial peptides in the scorpion Mesobuthus eupeus
Characterization of two linear cationic antimalarial peptides in the scorpion Mesobuthus eupeus
复制标题
蝎子 Mesobuthus eupeus 中两种线性阳离子抗疟肽的表征
DOI：
10.1016/j.biochi.2010.01.011
复制
发表时间：
2010-04-01
期刊：
影响因子：
3.9
通讯作者：
Zhu, Shunyi
中科院分区：
文献类型：
--
作者：
Gao, Bin;Xu, Jia;Zhu, Shunyi
恶性疟原虫是一种人类疟疾的病原体，由于其耐药性的不断增强，每年导致数百万人死亡，因此迫切需要新的抗疟药物。在这项工作中，我们报道了两个从中华钳蝎毒腺中克隆的基因，它们编码的多肽可以抑制伯氏疟原虫的发育，杀死红内期恶性疟原虫，并在微摩尔浓度下对果蝇S2细胞具有毒性。其中一个由24个氨基酸组成的多肽(命名为meucin-24)与蝎子毒长链K+通道毒素家族(LcKTx)和两个蛙类抗菌肽(mainin1和2)的氨基末端具有很高的序列同源性。对meucin-24的基因组DNA进行测序，结果表明该短肽是一种假设的鸟嘌呤到腺嘌呤的RNA编辑的产物，该RNA编辑自一条真地分枝杆菌的LcKTx转录本。另一种名为meucin-25的多肽含有25个残基，与任何已知的多肽没有序列相似性。化学合成肽的圆二色谱分析表明，Meucin-24在水中呈基本的无规卷曲构象，但在50%三氟乙醇存在下，其α螺旋含量大大增加，这是一个仿膜环境。这一发现进一步被其核磁共振结构所证实，该结构显示在残基4-20区域具有α-螺旋两亲性结构。CD结果表明，Meucin-25在水中主要采用β-折叠结构，而TFe促进了其α-螺旋的形成，表明其构象柔性。在不损害哺乳动物细胞(红细胞和GC-2细胞)的情况下杀灭红细胞内恶性疟原虫使它们成为抗疟疾药物设计的有吸引力的候选药物。(C)2010年爱思唯尔·马森公司。版权所有。
Plasmodium falciparum is a pathogen of human malaria which causes millions of deaths per year due to the ever-increasing drug resistance by the parasite, and thus novel antimalarial agents are urgently needed. In this work, we report two cDNA clones from the scorpion Mesobuthus eupeus venom gland, which encode peptides inhibiting the development of Plasmodium berghei, killing intraerythrocytic P. falciparum, and toxic to the Drosophila S2 cell at micromolar concentrations. One peptide of 24 amino acids (named meucin-24) shares high sequence identity to the amino-terminus of a family of scorpion venom long-chain K+ channel toxins (LcKTx) and two frog antimicrobial peptides (magainin1 and 2). Sequencing genomic DNA of meucin-24 identified this short peptide as a product of a putative guanine-to-adenine RNA editing from a M. eupeus LcKTx transcript. Another peptide, named meucin-25, contains 25 residues and does not share sequence similarity with any known peptides. Circular dichroism analysis of chemically synthesized peptides demonstrates that meucin-24 presents an essential random coil conformation in water, but its alpha-helical content largely increases in the presence of 50% trifluoroethanol, a membrane-mimicking environment. This finding was further verified by its NMR structure that showed an alpha-helical amphipathic architecture in the region of residues 4-20. CD results indicate that meucin-25 mainly adopts a beta-sheet structure in water but TFE promotes its alpha-helical formation, suggesting its conformational flexibility. Killing of intraerythrocytic P. falciparum without harming mammalian cells (erythrocytes and GC-2 cell) make them attractive candidates for antimalarial drug design. (C) 2010 Elsevier Masson SAS. All rights reserved.