Purification, characterization and functional expression of a new peptide with an analgesic effect from Chinese scorpion Buthus martensii Karsch (BmK AGP-SYPU1).

In this study, a new peptide named BmK AGP-SYPU1 with an analgesic effect was purified from the venom of Chinese scorpion Buthus martensi Karsch (BmK) through a four-step chromatographic process. The mouse twisting test was used to identify the target peptides in every separation step. The purified BmK AGP-SYPU1 was further qualified by RP-HPLC and HPCE. The molecular mass determined by the MALDI-4800-TOF/TOF MS for BmK AGP-SYPU1 was 7544 Da. Its primary structure of the N-terminal was obtained using Edman degradation. The gene sequence of BmK AGP-SYPU1 was cloned from the cDNA pool and genomic of scorpion glands, respectively, and then expressed in Escherichia coli. The sequence determination showed that BmK AGP-SYPU1 was composed of 66 amino acid residues with a new primary structure. The metal chelating affinity column and cation exchange chromatography were used to purify the recombinant BmK AGP-SYPU1. Consequently, the native and recombinant BmK AGP-SYPU1 showed similar analgesic effects on mice as assayed using a mouse twisting model. These results suggested that BmK AGP-SYPU1 is a new analgesic component found in the Chinese scorpion Buthus martensi Karsch.