利用1H NMR和限制分子動力模擬研究hNPY[21-31]的螺旋結構之摺疊

Folding of the helical structure of hNPY[21-31 by 1H NMR and restrained molecular dynamics.

游達(Ta Yu)

指導教授 ： 李長欣

淡江大學/理學院/化學學系碩士班/碩士(2008年)

https://doi.org/10.6846/TKU.2008.01119

摘要

人類神經胜肽Y(Human Neuropeptide Y, hNPY)在水溶液中具有α-helix結構，在nM濃度下為單體，mM濃度時則為雙體。hNPY與receptor作用時，則必須先以單體的結構與細胞膜結合，並在膜上以擴散作用至receptor而產生生理作用。
固相胜肽合成法(Solid Phase Peptide Synthesis)合成hNPY片段(hNPY[21-31]) [YSALRHYINLI]，經由高效能液相層析儀純化，質譜儀確認分子量，最後以二維核磁共振(two-dimensional NMR)的光譜: TOCSY、NOESY、[1H, 13C]-HSQC之光譜判定與光譜循序判定得到化學位移與限制條件。由DOSY實驗得知分子擴散係數，經公式計算得知hNPY[21-31]部份為雙體的結構。

最後經由Xplor-nih計算軟體算出得知結構，hNPY[21-31]在285K的狀態下產生螺旋結構的序列在23-29；310K之下則為24-29。經由模擬焠熄實驗之後得到的結果加以堆疊出285K、310K主幹RMSD分別為0.86、1.89。

關鍵字

核磁共振 ； 神經胜肽 ； 固相胜肽合成.

並列摘要

A part of conformation of human Neuropeptide Y (hNPY) in solution is α-helix. It's monomer in low concentration (nM) and dimer in high concentration (mM). It has to binding with cell membrane in monomer and diffuse to receptor before binding with receptor. hNPY[21-31] was synthesizd by solid phase peptide synthesis (SPPS ) and purified by HPLC. We checked the molecular weight of peptide by ESI-MASS. We used 2-D NMR and got chemical shifts and NMR restraints by TOCSY, NOESY and HSQC. By DOSY and calculation of diffusion coefficients, we found that there were dimmer in part of hNPY[21-31].
Finally, we got structures by XPLOR-NIH and found that there were resides 23-29 to form helix in 285K and resides 24-29 to form in 310K. RMSD were 0.86 in 285K and 1.89 in 310K by calculating molecular-dynamics refinements.

並列關鍵字

2D NMR ； NPY ； SPPS.

參考文獻

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