title: Soluble expression, purification and the role of C-terminal glycine residues in scorpion toxin BmK AGP-SYPU2.
abstract: The existence of glycine residues in long-chain scorpion toxins has been well documented. However, their role as analgesics has not been evaluated. To address this issue, we investigated the functional role of glycines in the C-terminal end of Chinese-scorpion toxin from Buthus martensii Karsch (BmK AGP-SYPU2) using site-directed mutagenesis and analgesic activity assays. Recombinant BmK AGP-SYPU2 and its mutants were efficiently expressed in E. coli and purified to homogeneity using immobilized metal ion affinity chromatography (IMAC) and cation exchange chromatography. The mouse-twisting test was used to detect the analgesic activity of BmK AGP-SYPU2 and its mutants. As a result, we identified glycines at the C-terminal end that, when altered, significantly affected analgesic activity. Also, Mut6566 was significantly decreased compared to BmK AGP-SYPU2. These data indicate that the glycines at the C-terminal end are important for the analgesic activity of BmK AGP-SYPU2.
authors.affiliation: School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, Shenyang, Liaoning Province 110016, P.R. China.
authors.forename: Rong
authors.initials: R
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Cui
authors.forename: Xi
authors.initials: X
authors.lastname: Zhang
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Yang
authors.forename: Yongshan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Yongbo
authors.initials: Y
authors.lastname: Song
authors.forename: Chunfu
authors.initials: C
authors.lastname: Wu
authors.forename: Jinghai
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005998:Glycine / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012604:Scorpion Venoms / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012605:Scorpions / Q000378:metabolism; D016415:Sequence Alignment; D014118:Toxins, Biological / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D012604:Scorpion Venoms; D014118:Toxins, Biological; D005998:Glycine