水-固相磷脂酶D催化反应体系合成磷脂酰甘油

Aqueous-solid system for phospholipase D-catalyzed transphosphatidylation to produce phosphatidylglycerol

构建了高效环保的水-固相磷脂酶D(PLD)催化反应体系用于磷脂酰基转移合成磷脂酰甘油(PG)。通过共价结合曲拉通的纳米二氧化硅载体在纯水相中实现磷脂(PC)吸附,载体上的PC在PLD催化下进行水-固界面磷脂酰基转移合成PG。系统研究了载体表面曲拉通质量摩尔浓度对PC的吸附,当载体表面曲拉通质量摩尔浓度为8.5×10^-8mol/g时,PC在载体上的吸附率达98%,PG转化率达90.5%。反应动力学符合PC限制的Michaelis-Menten方程。相比于传统双液相反应体系,水-固反应体系避免了有毒易挥发溶剂的使用;转酯反应温度及pH值操作范围扩大;可实现游离酶与载体的回收再利用,游离酶重复利用7次后PG相对产率仍高达80%,载体使用16次后PC吸附量和PG产率无明显下降。

A highly efficient and environmentally friendly aqueous-solid system for phospholipase D-catalyzed transphosphatidylation was established to produce phosphatidylglycerol(PG).Triton X-100 was covalently bound to the surface of nanosilica,and Triton X-100-modified nanosilica obtained was used for the adsorption of phosphatidylcholine(PC)in the purely aqueous solution.PG was successfully synthesized using the carrier-adsorbed PC under PLD-catalyzed transphosphatidylation.The effect of the content of Triton X-100 on the surface of nanosilica on transphosphatidylation was investigated systematically.The optimal value of Triton X-100 content on the surface of nanosilica was 8.5×10^-8 mol/g.Results indicated that the highest PC loading and yield of PG reached 98%and 90.5%,respectively.The reaction kinetics conforms to the PC-limited Michaelis-Menten equation.Compared with the traditional liquid-liquid system,the aqueous-solid reaction system avoids the use of toxic and volatile solvents,the tolerance of temperature and pH in our aqueous-solid reaction system were also improved significantly.The recyclability and stability of free PLD solution were studied,the relative yield of PG was still up to 80%in the seventh batch.The carrier was recycled for 16 times,the adsorption capacity of PC and the yield of PG did not obviously decrease.