| 摘要: |
| 从一株海洋放线菌株HY-G 中纯化得到了一种胞内中性β-葡萄糖苷酶。通过SDS-聚丙烯酰胺凝胶电泳和Superdex 200 凝胶柱层析估计酶分子质量分别是43.3 kD 和45.0 kD, 两者估计值接近, 表明该酶是一个单聚体, 不含亚基。采用对硝基酚基-β-D-葡萄糖苷(p-NPG)做底物, 测得该酶的最适pH 和最适温度分别为pH 7.5 和40 °C。该酶在pH 6.0～7.0 最稳定, 在70 °C 保温30 min 仍能保留56%的酶活力, 表明具有一定的温度稳定性。基于16S rRNA 基因的分类研究表明, 该菌株属于拟诺卡氏菌属。 |
| 关键词: 中性β-葡萄糖苷酶 海洋放线菌 拟诺卡氏菌 酶性质 |
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| 基金项目:中央财政支持地方高校发展专项资金-应用海洋生物学科研创新团队项目(CXTD20); 江苏省海洋生物技术重点实验室开放课题(2010HS05); 淮海工学院引进人才启动基金项目(KQ08015)资助 |
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| An intracellular neutral β-glucosidase from marine Nocardiopsis sp. HY-G |
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| Abstract: |
| An intracellular neutral β-glucosidase was isolated from a marine actinomycetes strain HY-G. The molecular weight of the β-glucosidase was confirmed to be 43.3 kD, by Sodium Dodecyl Sulphate Polyacryl Amide Gel Electrophoresis (SDS-PAGE)and 45.0 kD by size exclusion chromatography. suggesting it might be a monomer. The optimal pH and temperature for p-nitrophenyl-β-D-glucopyranoside (p-NPG) hydrolysing were around 7.5 and 40 °C, respectively. The β-glucosidase was most stable at pH 6.0-7.0, and retained 56% activity under 70 °C for 30 min. The taxonomy based on 16S rRNA gene suggested that strain HY-G belongs to genus Nocardiopsis. |
| Key words: neutral β-glucosidase marine actinomycetes Nocardiopsis enzymological characteristics |
