【摘要】 用不同的氨基保护的消旋氨基酸或酯作为羧基组分，在α－胰凝乳蛋白酶或木瓜蛋白酶的催化下与另一氨基酸的酰胺或酯缩合形成预期的光活性肽产物．以Ｌ－构型底物计算肽的产率为５５％～８３％，化合物的物理学常数与用相应的Ｎ－保护－Ｌ－氨基酸或酯为羧基组分，分别用化学法或酶促法测定所得结果一致．研究结果表明：利用酶的立体专一性，在形成肽键的过程中进行立体选择可得到光学活性的产物而不需预先拆分；只要溶剂体系中含有酶所需要的微量必需水，酶促反应在有机溶剂中可以顺利地进行．更多还原

【Abstract】 Condensation of the N-Z-or N-Boc-protected DL-amino acids(or esters)withGlyNHNHPh in the presence of papain at pH=5.0(or 8.2)or α-chymotrypsin at pH=10.0formed the expected optically active protected oligopeptides. The reaction was carried out inan aqueous-organic mixed solvent system and non-aqueous solvent system.These results indicate that the amino acid ester as acyl donor was better than the corresponding acid.The GlyNHNHPh as nucleophilic reagent was better than the correspondingester. Both thermal and storage stabilities of α- chymotrypsin are greatly enhanced in nonaqueous solvents compared with water system.The enzymatic peptide synthesis could alsobe carried out in dichloromethane with micro essential water(0.25%)and satisfactory results could be obtained.更多还原