Canine gastrin-releasing polypeptide (cGRP, characterized as a bombesin-like 27-residue peptide) was synthesized by successive azide condensations of 7 peptide fragments of established purity, followed by deprotection with trifluoromethanesulfonic acid in trifluoroacetic acid. Prior to deprotection, the Met(O) residue in the protected cGRP was reduced by brief treatment with phenylthiotrimethylsilane in the presence of a catalytic amount of trimethylsilyl trifluoromethanesulfonate. The homogeneous HPLC-purified product induced a significant increase of immunoreactive gastrin level in rat plasma, like synthetic human GRP.
犬胃泌素释放
多肽(cGRP,其特征为类似于蚕豆蛋白的 27 个残基的
多肽)是通过连续缩合 7 个纯度已确定的
多肽片段,然后在
三氟乙酸中用
三氟甲磺酸进行脱保护而合成的。在去保护层之前,先用苯基
硫代三甲基
硅烷在一定量的
三氟甲磺酸三甲基硅酯催化下进行短暂处理,还原受保护 cGRP 中的 Met(O) 残基。经 HPLC 纯化的均相产物与合成的人 GRP 相似,能显著提高大鼠血浆中的免疫活性胃泌素
水平。