无机盐水合物对有机溶剂中酶促寡肽合成的影响

必需水的存在是酶在有机溶剂中保持活性的关键。本文研究了自由水初始水含量对有机溶剂中α－胰凝乳蛋白酶(α-chymotrypsin)和嗜热杆菌蛋白酶粗品(thermoase)催化合成寡肽的影响。用无机盐水合物Na2SO4·10H2O和Na2CO3·10H2O代替自由水重复了上述反应。实验表明，足量的无盐水合物能在有机溶剂中可逆地失去自射所带的结晶水，因而能代替自由水来提代酶所需的"必需水"，并有效地控制有机溶剂中酶促反应体系的水活度(αw)值，从而有利于肽键的形成。

Effect of salt hydrates on enzymatic oligopeptide synthesis in organic solvents

Essential water is very important fot the enzyme to keep its bioactivity in organic solvents. The effect of free water content on the synthesis of Z-Tyr-Gly-Gly-OEt and Z-Tyr-Gly-NHNHPh by α- chymotrypsin and Boc-Phe-Ala-NHNHPh by thermoase in various organic solvents, including dichloromethane, cyclohexane, ethyl acetate and toluene, was investigated. By replacing free water with salt hydrates such as Na2SO4·10H2O or Na2CO3·10H2O, the effect of salt hydrates on the above reaction systems was also discussed. The results indicated that essential water can be supplied by slat hydrates, and water activity (αw) of the synthetic reaction system can also be fixed by salt hydrates, both favoring the formation of peptide bonds.