期刊
BIOCHEMICAL ENGINEERING JOURNAL
卷 175, 期 -, 页码 -出版社
ELSEVIER
DOI: 10.1016/j.bej.2021.108151
关键词
Polyethylene terephthalate; PETase; Low modification; Structural transformations; PET degradation; Enhanced catalytic performance
资金
- National Key Research and Development Program of China [2018YFA0900702]
- National Natural Science Foundation of China [21621004]
The study demonstrates that low modification of PETase enzyme can significantly improve its catalytic efficiency and stability in degrading PET plastics. Modifying PETase with different monomers leads to structural changes in the enzyme, which contribute to enhanced catalytic performance.
Polyethylene terephthalate is one of the most widely used synthetic plastics. The accumulation of abandoned PET has brought an environmental problem. A recently reported PET hydrolase, PETase, displays an efficient decomposition to PET. Herein, we synthesized four PETase conjugates by modifying four types of monomers onto PETase, which were hydrophobic tert-butyl methacrylate (TBMA), hydrophilic hydroxyethyl methacrylate (HEMA), positively charged 2-(dimethylamino)ethyl methacrylate (DMAEMA), and negatively charged methacrylic acid (MA). Despite the low modification with an average number of 3-5 monomers on each enzyme molecule, all the PETase conjugates exhibited improved enzyme activity, and thermal and pH stability. Particularly, the catalytic efficiency (k(cat)/K-m) of TBMA-/DMAEMA-PETase toward bis-2(hydroxyethyl) terephthalate (BHET) increased 1.4 and 1.6-fold as compared with PETase. Characterizations by fluorescence and circular dichroism spectroscopy unraveled that the modification induced the structural transformations, including compact overall structure and opened substrate-binding pocket, which were in favor of the enhanced catalytic performance. Biodegradation against PET films by TBMA-/DMAEMA-PETase were 4.69 and 3.26-fold higher than PETase. The different catalytic performances of the enzyme conjugates for BHET and PET are considered due to the different interactions of the conjugates with the different substrates. The work demonstrated that the low modifications with hydrophobic and hydrophilic monomers were both effective in improving the catalytic performance toward PET degradation, especially for the hydrophobic and positively charged monomers.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据