State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
Mar Drugs. 2011 Jan 21;9(1):109-23. doi: 10.3390/md9010109.
An alginate lyase-producing bacterial strain, Pseudoalteromonas sp. SM0524, was screened from marine rotten kelp. In an optimized condition, the production of alginate lyase from Pseudoalteromonas sp. SM0524 reached 62.6 U/mL, suggesting that strain SM0524 is a good producer of alginate lyases. The bifunctional alginate lyase aly-SJ02 secreted by strain SM0524 was purified. Aly-SJ02 had an apparent molecular mass of 32 kDa. The optimal temperature and pH of aly-SJ02 toward sodium alginate was 50 °C and 8.5, respectively. The half life period of aly-SJ02 was 41 min at 40 °C and 20 min at 50 °C. Aly-SJ02 was most stable at pH 8.0. N-terminal sequence analysis suggested that aly-SJ02 may be an alginate lyase of polysaccharide lyase family 18. Aly-SJ02 showed activities toward both polyG (α-l-guluronic acid) and polyM (β-D-mannuronic acid), indicating that it is a bifunctional alginate lyase. Aly-SJ02 had lower K(m) toward polyG than toward polyM and sodium alginate. Thin layer chromatography and ESI-MS analyses showed that aly-SJ02 mainly released dimers and trimers from polyM and alginate, and trimers and tetramers from polyG, which suggests that aly-SJ02 may be a good tool to produce dimers and trimers from alginate.
从海洋腐烂海带中筛选到一株产褐藻胶裂解酶的细菌，假交替单胞菌 SM0524。在优化条件下，假交替单胞菌 SM0524 产褐藻胶裂解酶活力达到 62.6 U/mL，表明该菌是产褐藻胶裂解酶的优良菌株。从菌株 SM0524 中分泌的双功能褐藻胶裂解酶 aly-SJ02 被纯化。aly-SJ02 的表观分子量为 32 kDa。aly-SJ02 作用于褐藻酸钠的最适温度和 pH 分别为 50°C 和 8.5。aly-SJ02 在 40°C 时半衰期为 41 min，在 50°C 时半衰期为 20 min。aly-SJ02 在 pH8.0 时最稳定。N 端序列分析表明，aly-SJ02 可能属于多糖裂解酶家族 18 的褐藻胶裂解酶。aly-SJ02 对聚 G（α-L-古洛糖醛酸）和聚 M（β-D-甘露糖醛酸）均有活性，表明它是一种双功能褐藻胶裂解酶。aly-SJ02 对聚 G 的 K(m)值低于对聚 M 和褐藻酸钠的 K(m)值。薄层层析和 ESI-MS 分析表明，aly-SJ02 主要从聚 M 和褐藻酸钠中释放二聚体和三聚体，从聚 G 中释放三聚体和四聚体，表明 aly-SJ02 可能是一种从褐藻酸钠中产生二聚体和三聚体的良好工具。
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