Development of systematic approach in determining three-dimensional structure of membrane bound biomolecules based on accurate interatomic distances

In this research project，we have studied to establish systematic approach in determining the three-dimensional structure of membrane bound biomolecules based on accurate interatomic distances obtained from solid state NMR。Following results were obtained in this research project.(1)The three-dimensional structure of[I D 113个D 1C，D 115D1N]-labeled Leu-enkephalin(tyr-Gly-Gly-Phe-Leu)dihydrate crystals was determined on the basis of six sets of accurately determined ID113I D1N interatomic distances by rotational echo double resonance(REDOR)and some additional constraints from I D113D1C chemical shifts.(2)The phenyl ring dynamics of[I D 12 D 1 D D 15 D 15 D 1 N]D1-enkephalin molecules in crystals grown from four solvents were examined using solid state ei D12文件D1H NMR spectroscopy.I D12的D1H NMR powder pattern clearly indicated the presence of 180°flip motions about the Cβ-Cγbond axis of the phenyl rings.The difference of…More the frequencies for the motion was attributed to the manner of their molecular packing in the crystal.(3)Conformational transition of human calcitonin(HCT)during fibril formation in the acidic and neutral condition were investigated by high resolution solid state I D 113个文件D1C NMR spectroscopy。The results indicate that conformational transitions fromα-helix toβ-sheet，and from random coil toβ-sheet forms occurred in the central and C-terminus regions，respectively，during fibril formation.(4)The conformation and dynamics of melittin bound to the d i m yristoylphophatidylcholin(DMPC)bilayer and the magnetic orientation in the lipid bilayer systems were investigated by solid-state I D 131D1P and the magnetic orientation in the lipid bilayer systems were investigated by solid-state D131D1P and D 113D1D.Using I D131文件D1P NMR，it was found that melittin-DMPC bilayer system forms magnetically oriented elongated vesicles with the long axis parallel to the magnetic field above the liquid crystalline-gel phase transition temperature.D 113个D 1C NMR spectra were observed on the D 113个D 1C labeled melittin bound to the lipid bilayer.Finally，it was found that melittin adopts a transmembraneα-helix whose average axis parallel to the bilayers normal.Less：Less

In this research project, we have studied to establish systematic approach in determining the three-dimensional structure of membrane bound biomolecules based on accurate interatomic distances obtained from solid state NMR. Following results were obtained in this research project.(1) The three-dimensional structure of [ィイD113ィエD1C, ィイD115ィエD1N]-labeled Leu-enkephalin (tyr-Gly-Gly-Phe-Leu) dihydrate crystals was determined on the basis of six sets of accurately determined ィイD113ィエD1C-ィイD115ィエD1N interatomic distances by rotational echo double resonance (REDOR) and some additional constraints from ィイD113ィエD1C chemical shifts.(2) The phenyl ring dynamics of [ィイD12ィエD1HィイD25ィエD2]PheィイD14ィエD1-labeled LeuィイD15ィエD1- and MetィイD15ィエD1-enkephalin molecules in crystals grown from four solvents were examined using solid state ィイD12ィエD1H NMR spectroscopy. ィイD12ィエD1H NMR powder pattern clearly indicated the presence of 180°flip motions about the Cβ-Cγbond axis of the phenyl rings. The difference of … More the frequencies for the motion was attributed to the manner of their molecular packing in the crystal.(3) Conformational transition of human calcitonin (hCT) during fibril formation in the acidic and neutral condition were investigated by high resolution solid state ィイD113ィエD1C NMR spectroscopy. The results indicate that conformational transitions from α-helix to β-sheet, and from random coil to β-sheet forms occurred in the central and C-terminus regions, respectively, during fibril formation.(4) The conformation and dynamics of melittin bound to the dimyristoylphophatidylcholin (DMPC) bilayer and the magnetic orientation in the lipid bilayer systems were investigated by solid-state ィイD131ィエD1P and ィイD113ィエD1C NMR spectroscopy. Using ィイD131ィエD1P NMR, it was found that melittin-DMPC bilayer system forms magnetically oriented elongated vesicles with the long axis parallel to the magnetic field above the liquid crystalline-gel phase transition temperature. ィイD113ィエD1C NMR spectra were observed on the ィイD113ィエD1C labeled melittin bound to the lipid bilayer. Finally, it was found that melittin adopts a transmembrane α-helix whose average axis is parallel to the bilayers normal. Less