Pimenta A M, Stöcklin R, Favreau P, Bougis P E, Martin-Eauclaire M F
UMR CNRS 6560, Université de la Méditerranée, Institut Jean Roche, Marseille, France.
Rapid Commun Mass Spectrom. 2001;15(17):1562-72. doi: 10.1002/rcm.415.
Scorpion venoms are very complex mixtures of molecules, most of which are peptides that display different kinds of biological activity. These venoms have been studied in the light of their pharmacological targets and their constituents are able to bind specifically to a variety of ionic channels located in prey tissues, resulting in neurotoxic effects. Toxins that modulate Na(+), K(+), Ca(++) and Cl(-) currents have been described in scorpion venoms. Mass spectrometry was employed to analyze toxic fractions from the venom of the Brazilian scorpion Tityus serrulatus in order to shed light on the molecular composition of this venom and to facilitate the search for novel pharmacologically active compounds. T. serrulatus venom was first subjected to gel filtration to separate its constituents according to their molecular size. The resultant fractions II and III, which account for 90 and 10% respectively of the whole venom toxic effect, were further analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS), on-line liquid chromatography/electrospray mass spectrometry (LC/ESMS) and off-line LC/MALDI-TOFMS in order to establish their mass fingerprints. The molecular masses in fraction II were predominantly between 6500 and 7500 Da. This corresponds to long-chain toxins that mainly act on voltage-gated Na(+) channels. Fraction III is more complex and predominantly contained molecules with masses between 2500 and 5000 Da. This corresponds to the short-chain toxin family, most of which act on K(+) channels, and other unknown peptides. Finally, we were able to measure the molecular masses of 380 different compounds present in the two fractions investigated. To our knowledge, this is the largest number of components ever detected in the venom of a single animal species. Some of the toxins described previously from T. serrulatus venom could be detected by virtue of their molecular masses. The interpretation of this large set of data has provided us with useful proteomic information on the venom, and the implications of these findings are discussed.
蝎毒是非常复杂的分子混合物，其中大部分是具有不同生物活性的肽。这些毒液已根据其药理靶点进行了研究，其成分能够特异性结合位于猎物组织中的各种离子通道，从而产生神经毒性作用。蝎毒中已发现可调节钠（Na⁺）、钾（K⁺）、钙（Ca²⁺）和氯（Cl⁻）电流的毒素。采用质谱分析法分析巴西蝎子锯齿脂鲤蝎（Tityus serrulatus）毒液的有毒成分，以阐明该毒液的分子组成，并有助于寻找新型药理活性化合物。首先对锯齿脂鲤蝎毒液进行凝胶过滤，根据其分子大小分离其成分。所得的组分II和III分别占整个毒液毒性作用的90%和10%，通过基质辅助激光解吸/电离飞行时间质谱（MALDI-TOFMS）、在线液相色谱/电喷雾质谱（LC/ESMS）和离线LC/MALDI-TOFMS进一步分析，以确定它们的质谱指纹。组分II中的分子质量主要在6500至7500道尔顿之间。这对应于主要作用于电压门控钠（Na⁺）通道的长链毒素。组分III更复杂，主要包含质量在2500至5000道尔顿之间的分子。这对应于短链毒素家族，其中大多数作用于钾（K⁺）通道以及其他未知肽。最后，我们能够测量所研究的两个组分中存在的380种不同化合物的分子质量。据我们所知，这是在单一动物物种毒液中检测到的最大数量的成分。根据其分子质量可以检测到一些先前描述的来自锯齿脂鲤蝎毒液的毒素。对这一大组数据的解释为我们提供了有关该毒液的有用蛋白质组学信息，并讨论了这些发现的意义。
