Purification, characterization and structural study of the neuro-peptides from scorpion Buthus martensi Karsch

Total 40 peptides were purified from the venom of B. martensi Karsch, and c haracterized on the basis of their molecular weight (ESI-MS), N-terminal se quence (5 residues) and the toxicity to mammals and insects. Among 29 long chain peptides (60-70 residues) a novel anti-insect toxin BmK alpha IT1 and a new anti-mammal toxin BmK IV were identified and their primary structure s were determined by Edman degradation. Besides, from 11 short chain peptid es (28-40 residues), three K+ channel inhibitors were identified and their action modes were investigated by the assay in acutely dissociated rat hipp ocampal neurons using whole-cell patch-clamp configuration. The solution st ructure of BmK I, the main toxin, was determined by 2D H-1-NMR spectroscopy and molecular modeling techniques.