| Scorpion venom neurotoxins are known to interact strongly with the ionic channels. Most of them constitute a family of low molecular weight, single-chain polypeptides, cross-linked by three or four intramolecular disulfide bridges. Because of their low molecular weight, high stability in denaturing conditions and high specific activity on the kinds of receptors, they have been widely used in studies of structure-function relationship and neurochemical mechanism.The Asian scorpion Buthus martensi Karch is a species belonging to the Buthidae family. It is widely distributed from northern China to Mongolia and Kerea. In Chinese traditional medicine, even at the present time, the whole scorpion is still used as a drug to treat neurological symptoms, such as incomplete paralysis and mimetic paralysis, chronic pain as well as anti-cancer and anti-thrombus. To discover the new type of neurotoxins and the active peptides, Buthus martensi Karch venom was subjected to chemical constituents studies. The toxicities on mammalian, effects on potassium and sodium and analgesic activity were also studied. The secondary structure of one of short chain scorpion toxins was also studied using 2D-NMR techniques. At last one of the potential analgesic peptide with low toxicity on mammalian was expressed in Kcoli. then purified to homogenous and the analgesic effect of recombinant peptide was also determined.Fourteen scorpion toxins were purified using kinds of chromatography techniques. Eleven were identified through amino acid composition analysis, mass spectral analysis and Edman degradation. Four of them are novel peptides and nominated BmK Ang M1, BmK ML, Martentoxin and Martentoxin I, respectively. The physico-chemical properties of another three peptides were also determined. These data suggested that they were also the novel peptides and named BmK S1, BmK S2, BmK S3, respectively.
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