title: Probing the active conformation of FGLamide allatostatin analogs with N-terminal modifications using NMR spectroscopy and molecular modeling.
abstract: The FGLamide allatostatins (ASTs) can inhibit the production of juvenile hormone in vitro, and they therefore are regarded as possible insect growth regulator candidates for pest control. To understand the structural features of the ASTs that cause the differences in their activity the pentapeptide and four N-terminal modifications of AST analogs (H17, K9, K10 and K23) were selected to investigate their conformations. From NMR spectroscopy and molecular modeling, it is clear that K23 and K9 have a type IV β-turn and a γ turn in DMSO, respectively. The pentapeptide, H17 and K10 form a flexible conformation. Our study indicates that this flexible conformation could be an important and indispensable structural element for activity, whereas the turn structure may not be especially significant for biological activity.
authors.affiliation: Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, PR China; Department of Cell and Systems Biology, University of Toronto, 25 Harbord St., Toronto, ON, Canada M5S 3G5; State Key Laboratory of the Discovery and Development of Novel Pesticide, Shenyang Research Institute of Chemical Industry Co. Ltd., Shenyang 110021, PR China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, PR China.
authors.forename: Xiao Qing
authors.initials: XQ
authors.lastname: Wu
authors.affiliation: Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, PR China.
authors.forename: Chuan Liang
authors.initials: CL
authors.lastname: Zhang
authors.affiliation: Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, PR China. Electronic address: yangxl@cau.edu.cn.
authors.forename: Xin Ling
authors.initials: XL
authors.lastname: Yang
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, 25 Harbord St., Toronto, ON, Canada M5S 3G5. Electronic address: stephen.tobe@utoronto.ca.
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Tobe
mesh_terms: D000595:Amino Acid Sequence; D006860:Hydrogen Bonding; D056004:Molecular Dynamics Simulation; D009479:Neuropeptides / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D017433:Protein Structure, Secondary
chemical_list: D009479:Neuropeptides; C076523:allatostatin
keywords: Allatostatin analogs; Molecular modeling; NMR spectroscopy