Halcurin, a polypeptide toxin from the sea anemone Halcurias sp., with a structural resemblance to type 1 and 2 toxins
Halcurin, a polypeptide toxin from the sea anemone Halcurias sp., with a structural resemblance to type 1 and 2 toxins
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DOI：
10.1016/s0041-0101(96)00143-2
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发表时间：
1997-04-01
期刊：
影响因子：
2.8
通讯作者：
Shiomi, K
中科院分区：
文献类型：
--
作者：
Ishida, M;Yokoyama, A;Shiomi, K
海葵Halcurias sp.的水提取物属于内腔棘鱼亚目，被发现对螃蟹具有潜在的致死性，尽管它在小鼠中既没有显示出致死活性，也没有溶血活性。用SephadexG-50凝胶过滤和TSKgelODS-120 T反相高效液相色谱法分离得到一种对螃蟹LD_（50）为5.8 μ g/kg的多肽毒素（命名为halcurin）。通过对天然分子及其酶片段的序列分析，阐明了含47个残基的halcurin的完整氨基酸序列。与已知的海葵多肽毒素（1-3型）（均来自睡莲亚目的成员）的比较揭示了halcurin与2型毒素的高序列同源性（49-74%）。此外，halcurin有几个残基保守的唯一类型的毒素。这些结果，以及Halcurias sp.是一个比Nynantheae成员更原始的物种的事实，表明1型和2型毒素是从一个共同的祖先进化而来的，其序列与halcurin更相似。(C)1997年爱思唯尔科学有限公司
The aqueous extract of the sea anemone Halcurias sp. belonging to the suborder Endocoelantheae was found to be potently lethal to crabs, although it showed neither lethal activity in mice nor hemolytic activity. A polypeptide toxin (named halcurin) with a LD50 of 5.8 mu g/kg against crabs was isolated by gel filtration on Sephadex G-50 and reverse-phase high-performance liquid chromatography on TSKgel ODS-120T. The complete amino acid sequence of halcurin comprising 47 residues was elucidated by sequence analyses of the native molecule and its enzymatic fragment. Comparison with the known sea anemone polypeptide toxins (types 1-3), which are all from members of the suborder Nynantheae, revealed a high sequence homology (49-74%) of halcurin with type 2 toxins. Also, halcurin has several residues conserved for only type toxins. These results, together with the fact that Halcurias sp. is a more primitive species than members of Nynantheae, suggest that type 1 and 2 toxins have evolved from a common ancestor with a sequence more similar to halcurin. (C) 1997 Elsevier Science Ltd.