海藻酸钠-壳聚糖固定化木瓜蛋白酶催化内吗啡肽的合成

反应体系以乙腈作为有机介质，在微水有机溶剂体系中以Boc-Trp-OH和Phe-NH2为底物，用海藻酸钠 壳聚糖固定化木瓜蛋白酶催化合成Trp-Phe-NH2时，产率为27.8%．在这一合成反应中,对pH值、离子强度、溶液含量、反应温度、酶用量和反应时间进行正交试验，证明pH是本合成过程的最重要影响因素．反应体系以乙腈为有机介质，在微水有机溶剂体系中以 Boc-Tyr-Pro-OMe和Trp-Phe-NH2为底物，用IPSAC催化合成Tyr-Pro-Trp-Phe-NH2，产率为35~2%．

Enzymatic Synthesis of Endomorphin by Immobilized Papain on Sodium Alginate-Chitosan

The enzymatic synthesis of endomorphins were carried out by immobilized papain on sodium alginate-chitosan (IPSAC). The reaction has been carried out in two steps. First, Trp-Phe-NH2 was obtained by Boc-Trp-OH coupling with Phe-NH2 using IPSAC catalyst in microaqueous acetonitrile system with a 27.8 % yielding as determined by high performance liquid chromatography (HPLC). The catalytic properties of IPSAC were examined by studying the dependence of pH, ionic strength, solution content, reaction temperature,enzyme loading and reaction time over the yields. The results of orthogonal experiments indicated that pH was the most significant factor that influenced this synthesis. Second, Boc-Tyr-Pro-OMe and Trp-Phe-NH2 were suspended into the microaqueous acetonitrile to produce Tyr-Pro-Trp-Phe-NH2 (endomorphin-1) with a 35.2% yield.