摘要本文介绍了利用蛋白酶在PBS缓冲体系下催化合成低聚L-亮氨酸乙酯、低聚L-苯丙氨酸甲酯及其混合物。蛋白酶催化反应相较传统的化学法更加迅捷方便，且绿色环保。我们采用了木瓜蛋白酶和菠萝蛋白酶在PH值为7至9.5的范围内反应15分钟至24小时进行检测。我们考察了酶，PH，温度，时间等条件对低聚氨基酸酯聚合度和产率的影响。根据不同的条件，产率约在10%-70%左右不等，聚合度约在2~20左右。反应时间越长，聚合度越高，低分子量的产物越少。71612

This paper describe the protease-catalyzed synthesis of oligo L-Leu ethyl ester， oligo L-Phe methyl ester and their mixture in phosphate buffer saline. Protease-catalyzed reaction is more convenient and quicker than conventional chemical routes, and more environment friendly. Papain and bromelain were studied to determined their activities for L-Leu-OEt and L-Phe-OMe at the PH ranging from 7 to 9.5 as well as the time ranging from 15 minites to 24 hours. We investgated the effects on the degree of polymerization and and yield including enzymes, PH, temperature and reaction time. The yield ranges from 10% to 70% and the degree of polymerization ranges from 2 to 20 according to the condition of the reaction. The more the time of the amino acid ester reacts, the higher the degree of polymerization and the less the low molecular weight we may get. 

毕业论文关键词：低聚肽； 蛋白酶催化； 水溶液；共齐聚

Keyword: oligopeptide； protease catalysis； aqueous solution；co-oligomerization

目    录

摘    要 3

目    录 4

1 引言： 5

2 正文： 7

2.1 研究目标 7

2.2 研究内容 7

2.3 实验部分 8

2.3.1 实验材料 8

2.3.2 低聚一元氨基酸的制备 9

2.3.3 低聚多元氨基酸的制备 11

2.3.4 后处理 11

2.3.5 仪器表征 11

2.4 各种条件对产率的影响 12

2.4.1 PH对低聚氨基酸产率的影响 12

2.4.2 反应温度对低聚氨基酸产率的影响 13

2.4.3 反应时间对低聚氨基酸的影响 14

2.4.4 低聚多元氨基酸的产率 15

2.5 表征与测试 16

2.5.1 质谱 16

2.5.2 核磁 19

3 结论： 19

参考文献 21