Enzyme Fusion Technology Research Team, Molecular Bioprocess Research Center, Jeonbuk Branch Institute, Korea Research Institute of Bioscience and Biotechnology, Jeonbuk 580-185, Republic of Korea.
Microbiol Res. 2010 Jul 20;165(5):384-91. doi: 10.1016/j.micres.2009.08.005. Epub 2009 Oct 23.
A gene encoding glucansucrase was identified in Leuconostoc lactis EG001 isolated from lactic acid bacteria (LAB) in Kimchi, a traditional Korean fermented food. The L. lactis EG001 glucansucrase gene consists of 4503 bp open reading frame (ORF) and encodes an enzyme of 1500 amino acids with an apparent molecular mass of 165 kDa. The deduced amino-acid sequence showed the highest amino-acid sequence identity (75%) to that of dextransucrase of L. mesenteroides. The gene was cloned and over-expressed in Escherichia coli strain. The recombinant enzyme was purified via Ni-NTA affinity chromatography and its enzymatic properties were characterized. The enzyme exhibited optimum activity at 30 degrees C and pH 5.0. In addition, the enzyme was able to catalyze the glycosylation of l-ascorbic acid to l-ascorbic acid 2-glucoside. The glycosylated product via EG001 glucansucrase has the potential as an antioxidant in industrial applications.
从韩国传统发酵食品泡菜中分离得到的乳酸乳球菌 EG001 中鉴定出一种编码葡聚糖蔗糖酶的基因。L. lactis EG001 葡聚糖蔗糖酶基因由 4503bp 开放阅读框 (ORF) 组成，编码 1500 个氨基酸的酶，其表观分子量为 165kDa。推导的氨基酸序列与肠膜明串珠菌的葡聚糖蔗糖酶具有最高的氨基酸序列同一性（75%）。该基因在大肠杆菌菌株中被克隆和过表达。重组酶通过 Ni-NTA 亲和层析进行纯化，并对其酶学性质进行了表征。该酶在 30°C 和 pH5.0 下表现出最佳活性。此外，该酶能够催化 l-抗坏血酸的糖基化反应生成 l-抗坏血酸 2-葡萄糖苷。通过 EG001 葡聚糖蔗糖酶生成的糖基化产物在工业应用中具有作为抗氧化剂的潜力。
