固定化γ-谷氨酰转肽酶催化合成γ-L-谷氨酰-L-半胱氨酸  

Enzymatic Synthesis of γ-L-Glutamyl-L-Cysteine with Immobilized γ-Glutamyltranspeptidase

作　　者：宋希文[1] 周治[1] 姚忠[1] 肖彦羚[1] 徐虹[1] 韦萍[1] 

机构地区：[1]南京工业大学食品与轻工学院,江苏南京210009

出　　处：《化学反应工程与工艺》2009年第5期420-425,共6页Chemical Reaction Engineering and Technology

基　　金：国家重点基础研究发展计划"973"项目(2009CB724706)

摘　　要：以环氧基树脂EupergitC250L为载体对B.subtilisNX-2GGT进行了共价固定化。固定化酶的最适作用pH为9.0,最适作用温度为60℃。固定化酶的热稳定性和贮存稳定性均较游离酶有显著的提高,经100d20个批次转化后,固定化残余酶活仍能保持初始值的80%左右。以固定化酶为催化剂,在反应条件为L-谷氨酰胺(Gln)20mmol/L、S-苄基-半胱氨酸(S-Bzl-cys)20mmol/L、酶浓度0.0375U/mL和pH9.0条件下,40℃水浴反应22h,转肽产物S-苄基-γ-L-谷氨酰-L-半胱氨酸(S-Bzl-GGC)得率为4.3mmol/L,较游离酶提高了11.96%。S-Bzl-GGC经酸解脱除保护基后可得γ-L-谷氨酰-L-半胱氨酸,产物纯度可达94.1%。γ-glutamyltranspeptidase(GGT)from B.subtilis NX-2 was immobilized onto Eupergit C250L via oxirane method.The optimal pH and temperature of immobilized GGT were 9.0 and 60 ℃.The thermal and storage stability of GGT were significantly increased after immobilization.The activity of remaining GGT was still exceed 80% of its initial activity after storage for 100 d and reused for 20 batches.At the conditions of L-Glutamine 20 mmol/L,S-benzyl-cysteine(S-Bzl-cys)20 mmol/L,immobilized GGT 0.037 5 U/mL and pH 9.0,a maximal product yield of 4.3 mmol/L was obtained after incubated at 40 ℃ for 22 h,resulting in an increase of 11.96% compared to that use free GGT as catalyst.The protecting group of S-Bzl-γ-L-glutamyl-L-cysteine was removed with trifluoromethanesulfonic acid.The purity of produced γ-L-glutamyl-L-cysteine(GGC)was 94.1%.

关 键 词：Γ-谷氨酰转肽酶 固定化 γ-L-谷氨酰-L-半胱氨酸 酶法合成 

分 类 号：TQ922[轻工技术与工程—发酵工程]