體抑素藥物活性片段直線型胜?之製備純化及光譜特性研究

Preparation and spectroscopic study of the somatostatin pharma-active linear peptide

包涵汝(Han-ru Bao)

指導教授 ： 錢偉鈞

朝陽科技大學/理工學院/應用化學系碩士在職專班/碩士(2012年)

摘要

原生體抑素(SRIF-14)由14個胺基酸所組成之環狀型胜?，其活性片段位於F6-F7-W8-K9-T10-F11，SRIF-14與跨膜受體鍵結展現調節神經、內分泌及新陳代謝作用等生化功能，當SRIF-14進入疏水環境中其螢光最高吸收波長(λnm)出現藍位移現象。表示W8所處的環境極性降低，但螢光強度未因分子之轉動自由度受到限制而增強反而出現消光現象。本實驗探討直線型體抑素生物活性片段自水溶液進入微胞環境所引發之螢光變化。所有胜?均使用固相胜?合成製備：六?活性片段(SRIF-6)及八?活性片段及其丙胺酸取代物(SRIF-8、SRIF-8 F6→A、SRIF-8 F7→A、SRIF-8 F11→A、SRIF-8 F6、7、11→A)，以高效能液相層析儀純化並由基質輔助雷射脫附游離飛行時間質譜儀鑑定分子量並核磁共振實驗結果結合螢光之變化，胜?於不同環境中(水溶液及SDS微胞環境)之螢光效應及胜?構型之關係。實驗結果顯示，胜?自水溶液進入微胞環境時皆產生藍位移及靜態消光現象，其中以SRIF-8 F7→A消光程度最小，其次為SRIF-8 F6、7、11→A，構型方面水溶液環境各胜?以無序殘捲存在，當進入微胞環境時，則引發β-迴路之區域性構型存在。綜合以上結果說明當體抑素活性片段進入微胞環境時引發區域性結構變化，使F7之芳香環支鏈與W8更加靠近，因而導致色胺酸螢光之消光現象。

關鍵字

體抑素活性片段 ； 體抑素

並列摘要

Six somatostatin analogues, all containing the pharmaceutical active site F6-F7-W8-K9-T10-F11, were prepared by solid phase peptide synthesis protocol, including a hexapeptide, SRIF-6, an octpeptide, SRIF-8, and the alanine substitute of the octapeptide, SRIF-8 F6→A、SRIF-8 F7→A、SRIF-8 F11→A、SRIF-8 F6、7、11→A. The effect on the fluorescent property of tryptophan residue with the introduction of SDS micellar was investigated by fluorescence and nuclear magnetic resonance spectroscopy. The micellar environment caused quench effect in the tryptophan fluorescent signal for all the six peptides, while SRIF-8 F7→A displayed the least obvious quenching effect among the six peptides. NMR results showed that, under SDS micellar environment, a β-turn can be observed in all the peptides. When entering into SDS micelle environment, conformational change occurs in the fragement of somatostatin pharmaceutical active site and induce the F7 aromatic side-chain to move toward the fluorophore of W8 and results in static quench in tryptophan fluorescent intensity.

並列關鍵字

somatostatin pharmaceutical active site ； somatostatin

參考文獻

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