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Agitoxin is a toxin found in the venom of the scorpion ''Leiurus quinquestriatus hebraeus'' (yellow scorpion). Other toxins found in this species include charybdotoxin (CTX). CTX is a close homologue of Agitoxin. 〔 〕 ==Structure== Agitoxin can be purified using HPLC techniques. Primary structure: Three types of agitoxin can be distinguished, each identified as comprising 38 amino acids. They are highly homologous, differing only in the identity of the residues at positions 7, 15, 29 and 31. Alignment of Agitoxins. Disulphide bonds are indicated beneath the alignment. *Agitoxin-1 Gly-Val-Pro-Ile-Asn-Val-Lys-Cys-Thr-Gly-Ser-Pro-Gln-Cys-Leu-Lys-Pro-Cys-Lys-Asp-Ala-Gly-Met-Arg-Phe-Gly-Lys-Cys-Ile-Asn-Gly-Lys-Cys-His-Cys-Thr-Pro-Lys (molecular weight = 4014.87 Da, molecular formula = C169H278N52O47S7) *Agitoxin-2 Gly-Val-Pro-Ile-Asn-Val-Ser-Cys-Thr-Gly-Ser-Pro-Gln-Cys-Ile-Lys-Pro-Cys-Lys-Asp-Ala-Gly-Met-Arg-Phe-Gly-Lys-Cys-Met-Asn-Arg-Lys-Cys-His-Cys-Thr-Pro-Lys (molecular weight = 4090.95 Da, molecular formula = C169H278N54O48S8) *Agitoxin-3 Gly-Val-Pro-Ile-Asn-Val-Pro-Cys-Thr-Gly-Ser-Pro-Gln-Cys-Ile-Lys-Pro-Cys-Lys-Asp-Ala-Gly-Met-Arg-Phe-Gly-Lys-Cys-Met-Asn-Arg-Lys-Cys-His-Cys-Thr-Pro-Lys (molecular weight = 4100.98 Da, molecular formula = C171H280N54O47S8, CAS Number 155646-23-4) Secondary and tertiary structure: Agitoxin consists of a triple-stranded antiparallel beta-sheet in which the C-terminal strand sits in the centre of the sheet, and a single alpha-helix covering one face of the beta-sheet (see image on the right). The cysteine side chains connect the beta-sheet and the helix via disulphide bonds to form the core of the molecule. The fold of agitoxin is homologous to the previously determined folds of scorpion venom toxins, classified as 'Scorpion short toxins' by Pfam. This fold, and the location of the disulphide bonds, are a shared element between toxins stemming from arthropods. The structure of agitoxin-2, has been determined by NMR. 〔 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Agitoxin」の詳細全文を読む スポンサード リンク
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