科微学术

微生物学通报

几丁质酶基因的克隆表达及酶学性质
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

基金项目:

福建省海洋经济创新发展区域示范项目(2014FJPT02);福建省中青年教师教育科研项目(JAT160054)


Cloning, expression and characterization of the chitinase gene from Vibrio sp. GR52
Author:
Affiliation:

Fund Project:

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 资源附件
  • |
  • 文章评论
    摘要:

    【背景】几丁质是自然界中储藏量仅次于纤维素的有机物,几丁质酶能降解几丁质生成几丁寡糖,实现废弃物的高值化利用,目前菌株产几丁质酶能力低限制了它的生产应用。【目的】克隆弧菌(vibrio sp.) GR52的几丁质酶基因,实现其在大肠杆菌中的异源表达,对分离纯化的重组几丁质酶进行酶学性质研究。【方法】以弧菌GR52菌株基因组DNA为模板,克隆得到几丁质酶基因GR52-1,构建重组基因工程菌BL21(DE3)/pET22b-chiGR52-1,诱导表达的产物通过Ni-NTA树脂纯化后进行酶学性质研究。【结果】重组酶的最适反应pH为6.0,在pH 5.0?10.0范围内37 °C保温1 h仍能保持85%以上的相对酶活力,具有较好的pH稳定性;最适反应温度为50 °C,在45 °C保温1 h其酶活力基本没有损失,在50 °C保温1 h其残余酶活力仍达60%;在1 mmol/L浓度下,Cu2+、Ca2+对该酶具有促进作用,Hg+对该酶具有明显的抑制作用;在5 mmol/L浓度下,Ni+对该酶具有一定的促进作用,Mn2+、Co2+、Li+、Fe2+、Hg+、SDS (十二烷基硫酸钠)对该酶具有明显的抑制作用。以胶体几丁质为底物时,动力学参数Km、Vmax、kcat分别为0.85 mg/mL、0.19 μmol/(mL·min)和7.02 s?1。底物特异性分析表明该重组酶能特异性降解几丁质。【结论】重组几丁质酶具有良好的酶学性质,为几丁质酶的开发应用奠定基础。

    Abstract:

    [Background] Chitin is the second most abundant natural resource next to cellulose. Chitinase can catalyze chitin into chitosan oligosaccharide which achieved high value utilization of waste. [Objective] The chitinase gene of Vibrio sp. GR52 was cloned and expressed in Escherichia coli, and the properties of recombinase were characterized. [Methods] The chitinase gene chiGR52-1 was cloned from the genomic DNA of Vibrio sp. GR52 and the recombinant strain BL21 (DE3)/pET22b-chiGR52-1 was constructed. The recombinase rchiGR52-1 was purified by Ni-NTA affinity chromatography and the enzymatic properties were studied. [Results] The optimum catalytic pH of rchiGR52-1 was 6.0. It was stabled in the pH range of 5.0 to 10.0 and could maintain more than 85% of its relative activity after incubation at 37 °C for 1 hour. The optimum catalytic temperature of the enzyme was 50 °C and 60% of enzyme activity was remained after incubation at 50 °C for 1 hour. At the concentration of 1 mmol/L, Cu2+ and Ca2+ had stimulation on rchiGR52-1, while Hg+ had significant inhibition. At the concentration of 5 mmol/L, Ni+ stimulated the chitinase, while Mn2+, Co2+, Li+, Fe2+, Hg+ and SDS inhibited the enzyme. The kinetic parameters Km, Vmax and kcat of rchiGR52-1 were 0.85 mg/mL, 0.19 μmol/(mL·min) and 7.02 s?1, respectively. Substrate specificity analysis showed that rchiGR52-1 could catalyze chitin specifically. [Conclusion] Recombinant chitinase has good enzymatic properties which provide a theoretical foundation for chitinase applications.

    参考文献
    相似文献
    引证文献
引用本文

郑家敏,梁燕辉,朱凡,叶秀云,林娟. 几丁质酶基因的克隆表达及酶学性质[J]. 微生物学通报, 2018, 45(5): 1027-1034

复制
分享
文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数:
历史
  • 收稿日期:
  • 最后修改日期:
  • 录用日期:
  • 在线发布日期: 2018-05-03
  • 出版日期: