2NDI

Solution structure of the toxin ISTX-I from Ixodes scapularis

2NDI の概要

• エントリーDOI: 10.2210/pdb2ndi/pdb
• NMR情報: BMRB: 26062
• 分子名称: Putative secreted salivary protein (1 entity in total)
• 機能のキーワード: toxin peptide, toxin
• 由来する生物種: Ixodes scapularis (blacklegged tick,deer tick,shoulder tick)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 4793.28

構造登録者

Hu, K. (登録日: 2016-06-01, 公開日: 2017-06-07, 最終更新日: 2024-10-30)

主引用文献

Rong, M.,Liu, J.,Zhang, M.,Wang, G.,Zhao, G.,Wang, G.,Zhang, Y.,Hu, K.,Lai, R.
A sodium channel inhibitor ISTX-I with a novel structure provides a new hint at the evolutionary link between two toxin folds.
Sci Rep, 6:29691-29691, 2016

PubMed Abstract: Members of arachnida, such as spiders and scorpions, commonly produce venom with specialized venom glands, paralyzing their prey with neurotoxins that specifically target ion channels. Two well-studied motifs, the disulfide-directed hairpin (DDH) and the inhibitor cystine knot motif (ICK), are both found in scorpion and spider toxins. As arachnids, ticks inject a neurotoxin-containing cocktail from their salivary glands into the host to acquire a blood meal, but peptide toxins acting on ion channels have not been observed in ticks. Here, a new neurotoxin (ISTX-I) that acts on sodium channels was identified from the hard tick Ixodes scapularis and characterized. ISTX-I exhibits a potent inhibitory function with an IC50 of 1.6 μM for sodium channel Nav1.7 but not other sodium channel subtypes. ISTX-I adopts a novel structural fold and is distinct from the canonical ICK motif. Analysis of the ISTX-I, DDH and ICK motifs reveals that the new ISTX-I motif might be an intermediate scaffold between DDH and ICK, and ISTX-I is a clue to the evolutionary link between the DDH and ICK motifs. These results provide a glimpse into the convergent evolution of neurotoxins from predatory and blood-sucking arthropods.

PubMed: 27407029
DOI: 10.1038/srep29691

実験手法

SOLUTION NMR