Identification of novel I-superfamily conopeptides from several clades of Conus species found in the South China Sea
Identification of novel I-superfamily conopeptides from several clades of Conus species found in the South China Sea
复制标题
南海发现的几个芋螺物种进化枝中新型 I 超家族芋肽的鉴定。
DOI：
10.1016/j.peptides.2009.06.036
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发表时间：
2009-10-01
期刊：
影响因子：
3
通讯作者：
Dai, Qiuyun
中科院分区：
文献类型：
--
作者：
Liu, Zhuguo;Xu, Ning;Dai, Qiuyun
芋螺肽的I-超家族代表了一类新的具有四个二硫键（-C-C-CC-CC-C-C-）的肽，根据不同的信号肽序列，其福尔斯分为三个类别（I-1、I-2和I-3）。I-超家族受到越来越多的关注，因为它靶向K+离子通道，这是芋螺毒素中相对罕见的功能。根据I-2-超家族芋螺毒素信号肽N端序列设计引物，从中国南海产的5种芋螺（Conus eburneus、Conus imperialis、Conus vitulinus、Conus emaciatus和Conus litteratus）毒管中分离得到11种新的I-超家族芋螺毒素。序列比对结果显示，除Eb11.3外，其余信号区均表现出中等程度的保守性。与11、12和13个芋螺毒素超家族信号肽的同源性分别为21.1%、38.5%和30.0%。成熟肽的范围从几乎相同的物种之间的高度分歧。与已报道的I-超家族芋螺毒素的进化树分析表明，其中9个属于12个超家族分支，但其中2个既不是I-1-和I-2-也不是I-3-超家族分支。值得注意的是，与I超家族芋螺肽的A、B和C组相比，一些肽在半胱氨酸间环中显示出显著不同的氨基酸残基，这表明它们可能具有不同的生物活性和功能。(C)2009 Elsevier Inc. All rights reserved.
The I-superfamily of Conus peptides represents a new class of peptides with four disulfide bridges (-C-C-CC-CC-C-C-) that falls into three (I-1, I-2 and I-3) categories according to the different signal peptide sequences. The I-superfamily has received increasing attention because it targets K+ ion channels, a function that is relatively rare in conotoxins. Herein we report 11 novel I-superfamily conotoxins from the venom ducts of five Cone snails (Conus eburneus, Conus imperialis, Conus vitulinus, Conus emaciatus and Conus litteratus) native to the South China Sea using a primer designed according to the N-terminus of the signal sequence of I-2-superfamily conotoxins. The alignment of sequences revealed that signal regions exhibited moderate conservation with the exception of Eb11.3 from C. eburneus with homologies of 21.1%, 38.5% and 30.0% to the signal peptides of 11, 12 and 13 superfamily conotoxins, respectively. The mature peptides ranged from almost identical to highly divergent between species. Analyses of the evolutionary trees of these peptides with those of reported I-superfamily conotoxins showed that nine of them fall in 12 superfamily clades, but two of them were neither I-1- and I-2- nor I-3-superfamily clades. Notably, some peptides exhibited significantly different amino acid residues in the intercysteine loops compared with group A, B and C of I-superfamily conopeptides, suggesting that they may have different bioactivities and functions. (C) 2009 Elsevier Inc. All rights reserved.