Solution Structure of BmP01 from the Venom of Scorpion Buthus martensii Karsch

Abstract

From the venom of scorpion Buthus martensii Karsch,a short peptide (BmP01, 29 amino acid residues) was isolated and characterized as previously reported (Lebren, R. R., et al. (1997) Eur. J. Biochem. 245, 457–464). It was shown to reduce 33% outward K+ channel (hippocampal neurons) currents at 10 μM. The solution structure of BmP01 was determined by 2D 1H NMR spectroscopy. The NOEs, coupling constants, and H-D exchange obtained from NMR spectroscopy were used in structural calculations. The conformation of BmP01 is composed of a short α-helix (Cys 3-Thr 12) and a two-stranded antiparallel β-sheet (Ala 15-Asp 20 and Lys 23-Pro 28). There are three disulfide bridges (Cys 3-Cys 19, Cys 6-Cys 24 and Cys 10-Cys 26) connecting the α-helix and β-sheet. Asp 20 to Lys 23 form a type II turn linking the two strands. Structural and electrostatic potential comparison between BmP01 and its analogues are also presented.