神經胜肽Y（neuropeptide Y，NPY）是神經胜肽家族的成員之一，最早是在1982年由豬的大腦分離出來的。成員的特色為均含有36個胺基酸殘基和在C端皆修飾為NH2。hNPY主要分布在中樞和末梢神經系統中，掌控人體許多重要的生理功能。這些功能是藉由hNPY 的C端α-helix與受器作用而產生的。 我們利用固相胜肽合成儀合成hNPY (20-36)，經由高效能液相層析儀純化，質譜儀確認分子量後，再利用圓二色光譜儀觀察不同比例TFE溶液下，二級結構的變化。最後在利用NMR實驗，如TOCSY、NOESY、DOSY和[13C,1H]-HSQC來研究NPY片段的結合狀態。 將NOE輸入X-PLOR經過距離幾何和分子動力計算，我們得到在310K、298K和283K的結構分別為α-helix由L24到R35、R25到R33和A23到Q34。DOSY實驗中，我們發現在30% TFE-d3下結構可能為雙體或三聚體；在10% D2O下，結構傾相為單體。 Neuropeptide Y (NPY) is a member of the NPY family, contain 36 residues and is C-terminally amidate. It was first isolated from porcin brain at 1982 and was show to be the most abundant neuropeptide in the mammalian central nervous system, but is also widely expressed in the peripheral nervous system. The variety of physiological effects attributed to NPY are the result of its activity at Y receptors by C-terminal α-helix. We synthesized hNPY (20-36) by SPPS, purified by HPLC and made sure the molecular weight by Mass. Using NMR data, TOCSY, NOESY, DOSY and [13C, 1H]-HSQC, to investigate associate state of the NPY fragment. NOE data were used as input for distance geometry, molecule dynamic calculation in X-PLOR. We observed the peptide conformation showed α-helix at L24-R35, R25-33 and A23-Q34 at 310 K, 298 K and 283 K, respectively. In DOSY data,we obtained that the structure may be a dimmer or trimer which existed in 30% TFE-d3. In addition, it may show the structure with monomer in 10% D2O.
