title: Site-directed mutagenesis of BmK AGP-SYPU1: the role of two conserved Tyr (Tyr5 and Tyr42) in analgesic activity.
abstract: In this study, the role of two conversed tyrosines (Tyr5 and Tyr42) from the scorpion toxin BmK AGP-SYPU1 was investigated with an effective Escherichia coli expression system. Site-directed mutagenesis was used to individually substitute Tyr5 and Tyr42 with hydrophobic or hydrophilic amino acids, and the extent to which these scorpion toxin BmK AGP-SYPU1 tyrosines contribute to analgesic activity was evaluated. The results of the mouse-twisting test showed that Tyr5 and Tyr42 are associated with the analgesic activity of the toxin because the analgesic activities of Y5F and Y42F were significantly increased compared with the rBmK AGP-SYPU1; however, the Y5W had decreased activity. The results of molecular simulation reveal the following: (1) for analgesic activity, the core domain of the scorpion toxin BmK AGP-SYPU1 is key and (2) for pharmacological function, Tyr42 is most likely involved when the core domain conformation is altered. These studies identify a new relationship between the structure and analgesic activity of the scorpion toxin BmK AGP-SYPU1 and are significant for further research and the application of analgesic peptides.
authors.affiliation: School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning Province, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Deng
authors.forename: Hong-Xia
authors.initials: HX
authors.lastname: Zhang
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Rong
authors.initials: R
authors.lastname: Zhang
authors.forename: Xue
authors.initials: X
authors.lastname: Wen
authors.forename: Yong-Bo
authors.initials: YB
authors.lastname: Song
authors.forename: Yong-Shan
authors.initials: YS
authors.lastname: Zhao
authors.forename: Lin
authors.initials: L
authors.lastname: Ma
authors.forename: Chun-Fu
authors.initials: CF
authors.lastname: Wu
authors.forename: Jing-Hai
authors.initials: JH
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000700:Analgesics / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D000818:Animals; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010455:Peptides / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology; D012604:Scorpion Venoms / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology*; D012605:Scorpions / Q000235:genetics*; D016415:Sequence Alignment; D014443:Tyrosine / Q000235:genetics
chemical_list: D000700:Analgesics; C416854:BmKbpp protein, Buthus martensii Karsch; D010455:Peptides; D011994:Recombinant Proteins; D012604:Scorpion Venoms; D014443:Tyrosine