An N-terminal nonapeptide fragment of bovine trypsinogen, H-l-Val-l-Asp-l-Asp-l-Asp-l-Asp-l-Lys-l-Ile-l-Val-Gly-OH, was synthesized via two routes and its susceptibility with trypsin was investigated. Protected derivatives, t-butyloxycarbonyl protected nonapeptide t-butyl ester and benzyloxycarbonyl protected nonapeptide benzyl ester, were prepared by stepwise elongation. Removal of the protecting groups was carried out by treatment with trifluoroacetic acid and hydro-genation respectively. The naked peptide was purified with chromatography on ECTEOLA cellulose column using dilute acetic acid as a solvent. Upon lyophilization the desired nonapeptide was obtained as colorless powder, a portion of the product being digested with trypsin. Rate of tryptic hydrolysis of the peptide was found to be unexpectedly low in the absence of calcium ion, while considerable acceleration of the hydrolysis by calcium ion was noted.
一种牛胰蛋白酶原的N-末端九肽片段H-l-Val-l-Asp-l-Asp-l-Asp-l-Asp-l-Lys-l-Ile-l-Val-Gly-OH通过两条途径合成,并研究了其与胰
蛋白酶的敏感性。通过逐步延伸的方法制备了保护性衍
生物,分别为t-丁氧羰基保护的九肽t-丁酯和苄氧羰基保护的九肽苄酯。去除保护基团是通过分别用
三氟乙酸和氢化处理进行的。裸肽通过在
ECT
EOLA纤维素柱上用稀
醋酸作为溶剂的色谱法进行纯化。冷冻干燥后,获取了无色粉末的目标九肽,部分产品与胰
蛋白酶消化。发现在缺乏
钙离子的情况下,肽的胰
蛋白酶水解速率意外地较低,而发现
钙离子显著加速了其
水解。