Characterization of a novel peptide toxin from Acanthoscurria paulensis spider venom: a distinct cysteine assignment to the HWTX-II family.
Characterization of a novel peptide toxin from Acanthoscurria paulensis spider venom: a distinct cysteine assignment to the HWTX-II family.
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DOI：
10.1021/bi4000035
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发表时间：
2013-03
期刊：
影响因子：
2.9
通讯作者：
Caroline F. B. Mourão;Mari D. Heghinian;E. Barbosa;F. Marí;C. Bloch;R. Restano-Cassulini;L. Possani;E. F. Schwartz
中科院分区：
文献类型：
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作者：
Caroline F. B. Mourão;Mari D. Heghinian;E. Barbosa;F. Marí;C. Bloch;R. Restano-Cassulini;L. Possani;E. F. Schwartz
蜘蛛毒液毒素引起了人们对寻找新药和杀虫剂的兴趣。然而，很少有研究与狼蛛毒素，特别是在巴西发现的物种进行。本研究旨在对首次从巴西短尾鳄蛇毒中分离到的毒素进行化学和生物学特性的研究。Ap 1a由48个氨基酸残基组成，分子量为5457.79 Da，克隆的基因编码23个氨基酸残基的信号肽和27个氨基酸残基的前肽推定序列。成熟肽的序列与HWTX-II家族毒素的序列具有60-84%的同一性。与这些毒素提出的结构模式不同，Ap 1a的二硫键配对是ICK型基序，这也是U1-TRTX-Bs 1a毒素所共有的。Ap 1a对草地贪夜蛾毛虫产生剂量依赖性且可逆的麻痹作用，注射后8小时的ED 50为13.0 ± 4.2 μg/g。在果蝇巨纤维回路中，Ap 1a（1.14-22.82 μg/g）降低了GF-TTM和GF-DLM通路的反应幅度和频率，表明在神经肌肉接头处的作用，这是由谷氨酸能受体介导的。对小鼠也具有致死性（1.67 μg/g，颅内途径），诱导的效应与脑室内给予NMDA所报告的效应相似。Ap 1a（1 μM）不会改变乙酰胆碱诱导的横纹肌肉瘤细胞制备物的反应，并且对hNav1.2、hNav1.4、hNav1.5和hNav1.6通道无显著影响。由于其独特的序列和半胱氨酸分配给HWTX-II家族，Ap 1a是对该毒素家族的结构-功能研究的重要贡献。
Spider venom toxins have raised interest in prospecting new drugs and pesticides. Nevertheless, few studies are conducted with tarantula toxins, especially with species found in Brazil. This study aims to characterize chemically and biologically the first toxin isolated from Acanthoscurria paulensis venom. Ap1a consists of 48 amino acid residues and has a molecular mass of 5457.79 Da. The cloned gene encodes a putative sequence of 23 amino acid residues for the signal peptide and 27 for the pro-peptide. The sequence of the mature peptide is 60-84% identical with those of toxins of the HWTX-II family. Different from the structural pattern proposed for these toxins, the disulfide pairing of Ap1a is of the ICK type motif, which is also shared by the U1-TRTX-Bs1a toxin. Ap1a induced a dose-dependent and reversible paralytic effect in Spodoptera frugiperda caterpillars, with an ED50 of 13.0 ± 4.2 μg/g 8 h after injections. In the Drosophila melanogaster Giant Fiber circuit, Ap1a (1.14-22.82 μg/g) reduces both the amplitude and frequency of responses from GF-TTM and GF-DLM pathways, suggesting an action at the neuromuscular junction, which is mediated by glutamatergic receptors. It is also lethal to mice (1.67 μg/g, intracranial route), inducing effects similar to those reported with intracerebroventricular administration of NMDA. Ap1a (1 μM) does not alter the response induced by acetylcholine on the rhabdomyosarcoma cell preparation and shows no significant effects on hNav1.2, hNav1.4, hNav1.5, and hNav1.6 channels. Because of its unique sequence and cysteine assignment to the HWTX-II family, Ap1a is a significant contribution to the structure-function study of this family of toxins.