Barona Jacqueline, Batista Cesar V F, Zamudio Fernando Z, Gomez-Lagunas Froylan, Wanke Enzo, Otero Rafael, Possani Lourival D
Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca 62210, Mexico.
Biochim Biophys Acta. 2006 Jan;1764(1):76-84. doi: 10.1016/j.bbapap.2005.08.010. Epub 2005 Aug 26.
The Colombian scorpion Tityus pachyurus is toxic to humans and is capable of producing fatal accidents, but nothing is known about its venom components. This communication reports the separation of at least 57 fractions from the venom by high performance liquid chromatography. From these, at least 104 distinct molecular weight compounds were identified by mass spectrometry analysis. The complete amino acid sequences of three peptides were determined and the partial sequences of three others were also identified. Electrophysiological experiments conducted with ion-channels expressed heterologously on Sf9 cells showed the presence of a potent Shaker B K(+)-channel blocker. This peptide (trivial name Tpa1) contains 23 amino acid residues closely packed by three disulfide bridges with a molecular mass of 2,457 atomic mass units. It is the third member of the sub-family 13, for which the systematic name is proposed to be alpha-KTx13.3. The mice assay showed clearly the presence of toxic peptides to mammals. One of them named Tpa2, containing 65 amino acid residues with molecular mass of 7,522.5 atomic mass units, is stabilized by four disulfide bridges. It was shown to modify the Na(+)-currents of F-11 and TE671 cells in culture, similar to the beta scorpion toxins. These results demonstrate the presence of toxic peptides in the venom of T. pachyurus and confirm that accidents with this species of scorpion should be considered an important human hazard in Colombia.
哥伦比亚蝎子Tityus pachyurus对人类有毒，能够引发致命事故，但对其毒液成分却一无所知。本通讯报道了通过高效液相色谱法从该毒液中分离出至少57个组分。通过质谱分析从这些组分中鉴定出至少104种不同分子量的化合物。测定了三种肽的完整氨基酸序列，还鉴定出另外三种肽的部分序列。对在Sf9细胞上异源表达的离子通道进行的电生理实验表明存在一种强效的Shaker B K(+)通道阻滞剂。这种肽（俗名Tpa1）含有23个氨基酸残基，由三个二硫键紧密排列，分子量为2457原子质量单位。它是亚家族13的第三个成员，其系统名称拟为α-KTx13.3。小鼠实验清楚地表明存在对哺乳动物有毒的肽。其中一种名为Tpa2，含有65个氨基酸残基，分子量为7522.5原子质量单位，由四个二硫键稳定。它被证明能改变培养的F- . 11和TE671细胞的Na(+)电流，类似于β型蝎子毒素。这些结果证明了T. pachyurus毒液中存在有毒肽，并证实该种蝎子引发的事故在哥伦比亚应被视为对人类的一项重大危害。
