Irokawa A, Tominaga M
University of São Paulo.
Pept Res. 1991 Nov-Dec;4(6):340-6.
The tripeptide Z-Cys(Bzl)-Tyr-Ile-OtBu (I) has been synthesized by papain, chymotrypsin and thermolysin catalysis using two different strategies: a) starting from the C-terminal amino acid and b) starting from the N-terminal amino acid. The optimum reaction conditions for obtaining the peptides Z-Tyr-Ile-OtBu (II), Z-Cys(Bzl)-Tyr-OtBu (III) and Z-Cys(Bzl)-Tyr-Ile-OtBu (I) were established after analyses of the effects of pH, reaction time, concentrations of buffer, enzyme and substrates, relative proportions of the carboxyl to amine components and nature of the organic solvent on the coupling yield. The highest yields obtained for II and I using chymotrypsin and papain as catalysts were 74% and 45%, respectively. Starting from the N-terminal amino acid, and using papain and thermolysin as catalysts, the yields obtained were 91% for III and 92% for I. The effects of amine- and carboxyl-protecting groups on the extent of dipeptide synthesis catalyzed by chymotrypsin were also studied.
三肽Z-Cys(Bzl)-Tyr-Ile-OtBu（I）已通过木瓜蛋白酶、胰凝乳蛋白酶和嗜热菌蛋白酶催化，采用两种不同策略合成：a）从C端氨基酸开始；b）从N端氨基酸开始。在分析了pH、反应时间、缓冲液浓度、酶和底物浓度、羧基与胺组分的相对比例以及有机溶剂的性质对偶联产率的影响后，确定了获得肽Z-Tyr-Ile-OtBu（II）、Z-Cys(Bzl)-Tyr-OtBu（III）和Z-Cys(Bzl)-Tyr-Ile-OtBu（I）的最佳反应条件。以胰凝乳蛋白酶和木瓜蛋白酶为催化剂时，II和I的最高产率分别为74%和45%。从N端氨基酸开始，以木瓜蛋白酶和嗜热菌蛋白酶为催化剂，III的产率为91%，I的产率为92%。还研究了胺基和羧基保护基团对胰凝乳蛋白酶催化二肽合成程度的影响。
