Sampaio S V, Arantes E C, Prado W A, Riccioppo Neto F, Giglio J R
Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Brasil.
Toxicon. 1991;29(6):663-72. doi: 10.1016/0041-0101(91)90058-y.
Toxins T1IV (TsTX-III) and T2IV have been purified to homogeneity from Tityus serrulatus scorpion venom and further characterized. Their amino acid composition and SDS-PAGE reveal an approximate mol. wt of 7000. Their intracisternal LD50 (micrograms/kg) in mice were 12.9 +/- 1.6 and 3.0 +/- 0.5, while their N-terminal amino acid sequences were K-E-G-Y-A-M-D-H-E-G-C-K-F-S- and K-E-G-Y-L-M-D-H-E-G-C-K-L-S-C-F-I-R-P-S-G-Y-C-G-R-E-, respectively. This sequence of T2IV, its amino acid composition and its chromatographic and electrophoretic behaviour identify it as toxin gamma (TsTX-I), which is the major toxin from this venom. TsTX-III (13 to 102 micrograms/kg) produced a long lasting enhancement of the hypertensive effect of noradrenaline and a slight decrease of the hypotensive effect of acetylcholine, while T2IV (115 micrograms/kg) induced a prolonged hypotensive effect on the anesthetized rat. On the isolated guinea-pig vas deferens, TsTX-III (2.1 and 3.0 micrograms/ml) produced a horizontal shift of the dose-response curve for noradrenaline to the left with no change of the maximal response. At a concentration of 1.43 microM, it induced a prolongation of the duration of the B component of the compound action potential. This prolongation was strongly reduced after addition of tetrodotoxin.
毒素T1IV（TsTX - III）和T2IV已从锯齿蝎毒中纯化至同质，并进一步进行了特性鉴定。它们的氨基酸组成和SDS - PAGE显示其分子量约为7000。它们在小鼠脑池内的半数致死剂量（微克/千克）分别为12.9±1.6和3.0±0.5，而它们的N端氨基酸序列分别为K - E - G - Y - A - M - D - H - E - G - C - K - F - S - 和K - E - G - Y - L - M - D - H - E - G - C - K - L - S - C - F - I - R - P - S - G - Y - C - G - R - E - 。T2IV的这一序列、其氨基酸组成以及其色谱和电泳行为表明它是毒素γ（TsTX - I），这是该毒液中的主要毒素。TsTX - III（13至102微克/千克）使去甲肾上腺素的升压作用持久增强，乙酰胆碱的降压作用略有降低，而T2IV（115微克/千克）对麻醉大鼠诱导出持久的降压作用。在离体豚鼠输精管上，TsTX - III（2.1和3.0微克/毫升）使去甲肾上腺素的剂量 - 反应曲线向左水平移动，最大反应无变化。在浓度为1.43微摩尔/升时，它诱导复合动作电位B成分的持续时间延长。加入河豚毒素后，这种延长作用大大减弱。
