The Cuban scorpion Rhopalurus junceus (Scorpiones, Buthidae): component variations in venom samples collected in different geographical areas

Backgound The venom of the Cuban scorpion Rhopalurus junceus is poorly study from the point of view of their components at molecular level and the functions associated. The purpose of this article was to conduct a proteomic analysis of venom components from scorpions collected in different geographical areas of the country. Results Venom from the blue scorpion, as it is called, was collected separately from specimens of five distinct Cuban towns (Moa, La Poa, Limonar, El Chote and Farallones) of the Nipe-Sagua-Baracoa mountain massif and fractionated by high performance liquid chromatography (HPLC); the molecular masses of each fraction were ascertained by mass spectrometry analysis. At least 153 different molecular mass components were identified among the five samples analyzed. Molecular masses varied from 466 to 19755 Da. Scorpion HPLC profiles differed among these different geographical locations and the predominant molecular masses of their components. The most evident differences are in the relative concentration of the venom components. The most abundant components presented molecular weights around 4 kDa, known to be K+-channel specific peptides, and 7 kDa, known to be Na+-channel specific peptides, but with small molecular weight differences. Approximately 30 peptides found in venom samples from the different geographical areas are identical, supporting the idea that they all probably belong to the same species, with some interpopulational variations. Differences were also found in the presence of phospholipase, found in venoms from the Poa area (molecular weights on the order of 14 to 19 kDa). The only ubiquitous enzyme identified in the venoms from all five localities studied (hyaluronidase) presented the same 45 kD molecular mass, identified by gel electrophoresis analysis. Conclusions The venom of these scorpions from different geographical areas seem to be similar, and are rich in peptides that have of the same molecular masses of the peptides purified from other scorpions that affect ion-channel functions.

研究背景
目前对于古巴蝎（Rhopalurus junceus）的毒液，从其分子层面的组分以及相关功能的角度而言，相关研究仍较为匮乏。本文旨在对采集自该国不同地理区域的蝎子的毒液组分开展蛋白质组学分析。
结果
该物种俗称蓝蝎，研究人员从古巴尼佩-萨瓜-巴拉科阿山地群的5个不同城镇（莫阿、拉波阿、利莫纳尔、埃尔乔特和法拉隆内斯）的蝎标本中分别采集其毒液，通过高效液相色谱法（high performance liquid chromatography，HPLC）进行组分分级，并借助质谱分析确定各分级组分的分子量。在所分析的5个样本中，共鉴定出至少153种不同分子量的组分，分子量分布范围为466至19755道尔顿（Da）。不同地理区域的蝎子其HPLC图谱以及组分的优势分子量均存在差异，最显著的差异体现在毒液组分的相对浓度上。丰度最高的组分分子量约为4 kDa和7 kDa，其中前者为钾离子通道特异性肽段，后者为钠离子通道特异性肽段，但二者之间存在细微的分子量差异。在不同地理区域的毒液样本中，共发现约30种完全相同的肽段，这支持了它们大概率属于同一物种、仅存在种群间差异的观点。此外，不同区域的毒液在酶类组分上也存在差异：波阿地区的毒液中含有磷脂酶，其分子量约为14至19 kDa。在所有5个采样区域的毒液中均检测到的唯一普遍存在的酶为透明质酸酶（hyaluronidase），经凝胶电泳分析确定其分子量均为45 kDa。
结论
来自不同地理区域的这类蝎子毒液组分整体相似，且均富含与其他蝎子中纯化得到的、影响离子通道功能的肽段分子量一致的肽类物质。