Infection Control Material Research Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup, 580-185, Korea.
Protein J. 2014 Feb;33(1):110-7. doi: 10.1007/s10930-013-9535-9.
A novel gene encoding thermostable endoglucanase was identified in Xanthomonas sp. EC102 from soil. The gene had 1,458 base pairs of open reading frame, which encode a 52-kDa protein of 486 amino acid residues. Sequence of the amino acid residues was similar with the endoglucanase from Xanthomonas campestris pv. campestris ATCC33913 (GenBank Accession No. NP_638867.1) (94 % identity). The endoglucanase was overexpressed in Escherichia coli BL21 and purified. Temperature for the highest enzymatic activity was 70 °C and pH optima was pH 5.5. The specific activity of the endoglucanase toward carboxymethylcellulose (CMC) was approximately 2 μmol min⁻¹ mg⁻¹, V max for CMC was 1.44 μmol mg⁻¹ min⁻¹, and K m values was 25.6 mg mL⁻¹. The EC102 endoglucanase was stable at temperatures up to 60 °C, and it was activated by 0.1 mM of Mn²⁺ and Co²⁺. This is the first report about thermostable endoglucanase from Xanthomonas sp.
从土壤中分离到的黄单胞菌 EC102 中发现了一个新的编码耐热内切葡聚糖酶的基因。该基因的开放阅读框有 1458 个碱基对，编码一个 52kDa 的 486 个氨基酸残基的蛋白质。氨基酸序列与野油菜黄单胞菌 pv. campestris ATCC33913 的内切葡聚糖酶（GenBank 登录号 NP_638867.1）相似（94%的同一性）。内切葡聚糖酶在大肠杆菌 BL21 中过表达并纯化。最适酶活温度为 70°C，最适 pH 值为 5.5。该内切葡聚糖酶对羧甲基纤维素（CMC）的比活力约为 2μmol min⁻¹ mg⁻¹，CMC 的 V max 为 1.44μmol mg⁻¹ min⁻¹，K m 值为 25.6mg mL⁻¹。EC102 内切葡聚糖酶在高达 60°C 的温度下稳定，并且被 0.1mM 的 Mn²⁺和 Co²⁺激活。这是第一个关于黄单胞菌属耐热内切葡聚糖酶的报道。
