Solution Structure of BmBKTx1, a New BK(Ca)(1) Channel Blocker from the Chinese Scorpion Buthus martensi Karsch(,).
Cai, Z., Xu, C., Xu, Y., Lu, W., Chi, C.W., Shi, Y., Wu, J.(2004) Biochemistry 43: 3764-3771
- PubMed: 15049683
- DOI: https://doi.org/10.1021/bi035412+
- Primary Citation of Related Structures:
1Q2K - PubMed Abstract:
BmBKTx1 is a 31-amino acid peptide identified from the venom of the Chinese scorpion Buthus martensi Karsch, blocking high-conductance calcium-activated potassium channels. Sequence homology analysis indicates that BmBKTx1 is a new subfamily of short-chain alpha-KTx toxins of the potassium channel, which we term alpha-KTx19. Synthetic BmBKTx1 was prepared by using solid-phase peptide synthesis. Two-dimensional NMR spectroscopy techniques were used to determine the solution structure of BmBKTx1. The results show that the BmBKTx1 forms a typical cysteine-stabilized alpha/beta scaffold adopted by most short-chain scorpion toxins. The structure of BmBKTx1 consists of a two-stranded antiparallel beta-sheet (residues 20-29) and an alpha-helix (residues 5-15). The three-dimensional structure of BmBKTx1 was also compared with those of two function-related scorpion toxins, charybdotoxin (ChTx) and BmTx1, and their structural and functional implications are discussed.
Organizational Affiliation:
Laboratory of Structural Biology, School of Life Science, University of Science and Technology of China, Hefei, Anhui, PRC.