Role of the structurally disordered N- and C-terminal residues in the Janus-faced atracotoxins
Role of the structurally disordered N- and C-terminal residues in the Janus-faced atracotoxins
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DOI：
10.1016/s0041-0101(02)00154-x
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发表时间：
2002-09-01
期刊：
影响因子：
2.8
通讯作者：
King, GF
中科院分区：
文献类型：
--
作者：
Maggio, F;King, GF
Janus-faced atracotoxins （J-ACTXs）是从澳大利亚漏斗网蜘蛛（Atrax属和Hadronyche属）的毒液中分离出来的一类昆虫特异性兴奋性毒素。除了一个经典的胱氨酸结基，这些毒素含有一个罕见的邻二硫键。虽然已知邻苯二硫对杀虫活性至关重要，但其他残留物在毒素功能中的作用仍有待确定。在这项研究中，我们利用一组原型家族成员J-ACTX-Hv1c的重组突变体，探讨了结构紊乱的N端和c端残基的作用。我们发现结构紊乱的c端残基（Glu 36和Pro 37）对于毒素功能是必不可少的。然而，虽然Ala 1的缺失对毒素功能的影响很小，但Ala 1和Ile 2的缺失使杀虫活性降低了70倍以上。我们认为il2是J-ACTX-Hv1c靶结合位点的一部分。(C) 2002 Elsevier Science Ltd.版权所有。
The Janus-faced atracotoxins (J-ACTXs) are a family of insect-specific excitatory toxins isolated from the venom of Australian funnel-web spiders (genera Atrax and Hadronyche). In addition to a classical cystine knot motif, these toxins contain a rare vicinal disulfide bond. While the vicinal disulfide is known to be critical for insecticidal activity, the role of other residues in toxin function remains to be determined. In this study, we probed the role of the structurally disordered N- and C-terminal residues using a panel of recombinant mutants of the prototypic family member J-ACTX-Hv1c. We found that the structurally disordered C-terminal residues (Glu 36 and Pro 37) were dispensable for toxin function. However, whereas deletion of Ala I had minimal impact on toxin function, deletion of both Ala 1 and Ile 2 decreased insecticidal activity more than 70-fold. We propose that Ile 2 forms a part of the target binding site of J-ACTX-Hv1c. (C) 2002 Elsevier Science Ltd. All rights reserved.