来源于西梅的(R)-醇腈酶促立体选择性转氰合成(R)-酮醇腈  

(R)-Oxynitrilase From Prunus salicina Catalysed Synthesis of (R)-Ketone-cyanohydrin by Enantioselective Transcyanation

作　　者：刘森林[1] 宗敏华[2] 

机构地区：[1]深圳大学生命科学学院,深圳518060 [2]华南理工大学生物工程系,广州510640

出　　处：《生物化学与生物物理进展》2010年第11期1212-1216,共5页Progress In Biochemistry and Biophysics

基　　金：国家自然科学基金(20376026);广东省自然科学基金(31349)资助项目~~

摘　　要：在水/有机溶剂双相反应体系中,研究了来源于西梅的(R)-醇腈酶催化酮与丙酮醇腈合成(R)-酮醇腈的立体选择性转氰反应.系统探讨了不同酶源、酶粉颗粒大小、底物浓度、两底物配比、酶浓度和底物结构对转氰反应的影响.结果发现西梅醇腈酶能高效催化三甲基硅酮与丙酮醇腈的立体选择性转氰.酶粉颗粒大小以直径0.3～0.45mm为优,底物浓度以21mmol/L左右为佳,底物丙酮醇腈与三甲基硅酮摩尔浓度比以2∶1为宜,酶浓度以60.9g/L左右为好.西梅醇腈酶对3,3-二甲基-2-丁酮几乎没有催化活性,而对其硅结构类似物三甲基硅酮却具有非常高的立体选择性和催化活性,在上述优化反应条件下反应24h的底物转化率和产物光学纯度均高达99%以上,表明底物中的硅原子对西梅醇腈酶的催化活性有非常显著的促进作用.The synthesis of optically active（R） -ketone-cyanohydrin catalyzed by（R） -oxynitrilase from Prunus salicina seed meal via enantioselective transcyanation of acetyltrimethylsilane with acetone cyanohydrin in the water/organic solvent biphasic system was studied by GC analysis on a chiralβ-Cyclodextrin Column.The effects of different（R） -oxynitrilase sources,diameter size of crude enzyme,substrate concentration,the ratio of two substrates,enzyme concentration and substrate structure on the enzymatic enantioselective transcyanation were investigated systematically.The results showed that（R） -oxynitrilase from Prunus salicina could efficiently catalyze enantioselective transcyanation of acetyltrimethylsilane with acetone cyanohydrin.The optimal diameter size of crude enzyme,concentration of acetyltrimethylsilane,ratio of acetone cyanohydrin to acetyltrimethylsilane and crude enzyme concentration were 0.3～0.45 mm,21 mmol/L,2∶1 and 60.9 g/L,respectively.（R） -oxynitrilase from Prunus salicina could not accept 3,3-dimethyl-2-butanone as substrate,while both high substrate conversion and high product ee%were obtained with its silicon counterpart acetyltrimethylsilane as the substrate.Under the optimal conditions,both acetyltrimethylsilane conversion and enantiomeric excess of the product were above 99%. These results demonstrated that the silicon atom in substrate served as a more effective atom than the carbon atom to enhance the activity of this enzyme.

关 键 词：西梅 (R)-醇腈酶 (R)-酮醇腈 立体选择性转氰 

分 类 号：Q556.1[生物学—生物化学]