1S8K

Solution Structure of BmKK4, A Novel Potassium Channel Blocker from Scorpion Buthus martensii Karsch, 25 structures

1S8K の概要

• エントリーDOI: 10.2210/pdb1s8k/pdb
• 関連するPDBエントリー: 1ACW 1DU9 1PNH 1SCY
• NMR情報: BMRB: 6109
• 分子名称: Toxin BmKK4 (1 entity in total)
• 機能のキーワード: alpha/beta scaffold, toxin
• 由来する生物種: Mesobuthus martensii (Chinese scorpion)
• 細胞内の位置: Secreted: Q95NJ8
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 3467.89

構造登録者

Zhang, N.,Chen, X.,Li, M.,Cao, C.,Wang, Y.,Hu, G.,Wu, H. (登録日: 2004-02-02, 公開日: 2005-02-08, 最終更新日: 2024-10-30)

主引用文献

Zhang, N.,Chen, X.,Li, M.,Cao, C.,Wang, Y.,Wu, G.,Hu, G.,Wu, H.
Solution structure of BmKK4, the first member of subfamily alpha-KTx 17 of scorpion toxins
Biochemistry, 43:12469-12476, 2004

PubMed Abstract: BmKK4 is a 30 amino acid peptide purified from the venom of the Chinese scorpion Buthus martensi Karsch. It has been classified as the first member of scorpion toxin subfamily alpha-KTx 17. The 3D structure of BmKK4 in solution has been determined by 2D NMR spectroscopy. This toxin adopts a common alpha/beta-motif, but shows a distinctive local conformation. The most novel feature is that the regular arrangements of the side chains of the residues involved in the beta-sheet of BmKK4 are distorted by a classic beta-bulge structure, which involves two residues (Asp18 and Arg19) in the first strand opposite a single residue (Tyr26) in the second strand. The bulge produces two main changes in the structure of the antiparallel beta-sheet: (1) It disrupts the normal alteration of the side chain direction; the side chain of Asp18 turns over to form a salt bridge with that of Arg19. (2) It accentuates the twist of the sheet, and alters the direction of the antiparallel beta-sheet. The unusual structural feature of the toxin is attributed to the shorter peptide segment (Leu15-Arg19) between the third and fourth Cys residues and two unique residues (Asp18 and Arg19) at the position preceding the fourth Cys. In addition, the lower affinity of the peptide for the Kv channel is correlated to the structural features: residue Arg19 instead of a Lys residue at the critical position for binding and the salt bridge formed between residues Arg19 and Asp18.

PubMed: 15449936
DOI: 10.1021/bi0490643

実験手法

SOLUTION NMR