1PVZ

Solution Structure of BmP07, A Novel Potassium Channel Blocker from Scorpion Buthus martensi Karsch, 15 structures

Summary for 1PVZ

• Entry DOI: 10.2210/pdb1pvz/pdb
• Related: 1ACW 1DU9 1PNH 1SCY
• NMR Information: BMRB: 5865
• Descriptor: K+ toxin-like peptide (1 entity in total)
• Functional Keywords: alpha/beta scaffold, toxin
• Biological source: Mesobuthus martensii (Chinese scorpion)
• Total number of polymer chains: 1
• Total formula weight: 3252.77

Authors

Wu, H.,Zhang, N.,Wang, Y.,Zhang, Q.,Ou, L.,Li, M.,Hu, G. (deposition date: 2003-06-29, release date: 2004-05-18, Last modification date: 2018-06-20)

Primary citation

Zhang, N.,Li, M.,Chen, X.,Wang, Y.,Wu, G.,Hu, G.,Wu, H.
Solution structure of BmKK2, a new potassium channel blocker from the venom of chinese scorpion Buthus martensi Karsch
PROTEINS, 55:835-845, 2004

PubMed Abstract: A natural K+ channel blocker, BmKK2 (a member of scorpion toxin subfamily alpha-KTx 14), which is composed of 31 amino acid residues and purified from the venom of the Chinese scorpion Buthus martensi Karsch, was characterized using whole-cell patch-clamp recording in rat hippocampal neurons. The three dimensional structure of BmKK2 was determined with two-dimensional NMR spectroscopy and molecular modelling techniques. In solution this toxin adopted a common alpha/beta-motif, but showed distinct local conformation in the loop between alpha-helix and beta-sheet in comparison with typical short-chain scorpion toxins (e.g., CTX and NTX). Also, the alpha helix is shorter and the beta-sheet element is smaller (each strand consisted only two residues). The unusual structural feature of BmKK2 was attributed to the shorter loop between the alpha-helix and beta-sheet and the presence of two consecutive Pro residues at position 21 and 22 in the loop. Moreover, two models of BmKK2/hKv1.3 channel and BmKK2/rSK2 channel complexes were simulated with docking calculations. The results demonstrated the existence of a alpha-mode binding between the toxin and the channels. The model of BmKK2/rSK2 channel complex exhibited favorable contacts both in electrostatic and hydrophobic, including a network of five hydrogen bonds and bigger interface containing seven pairs of inter-residue interactions. In contrast, the model of BmKK2/hKv1.3 channel complex, containing only three pairs of inter-residue interactions, exhibited poor contacts and smaller interface. The results well explained its lower activity towards Kv channel, and predicted that it may prefer a type of SK channel with a narrower entryway as its specific receptor.

PubMed: 15146482
DOI: 10.1002/prot.20117

Experimental method

SOLUTION NMR