Jiangsu Engineering Technology Research Centre for Functional Textiles, Jiangnan University, No.1800 Lihu Avenue, Wuxi, China.
Jiangsu Engineering Technology Research Centre for Functional Textiles, Jiangnan University, No.1800 Lihu Avenue, Wuxi, China; Mechanical Engineering College, Tarim University, Alar, Xinjiang, China.
Int J Biol Macromol. 2024 Jul;273(Pt 1):133049. doi: 10.1016/j.ijbiomac.2024.133049. Epub 2024 Jun 8.
To enhance the enzymatic digestibility of polyethylene terephthalate (PET), which is highly oriented and crystallized, a polyethylene glycol (PEG) surfactant of varying molecular weights was utilized to improve the stability of mutant cutinase from Humicola insolens (HiC) and to increase the accessibility of the enzyme to the substrate. Leveraging the optimal conditions for HiC hydrolysis of PET, the introduction of 1 % w/v PEG significantly increased the yield of PET hydrolysis products. PEG600 was particularly effective, increasing the yield by 64.58 % compared to using HiC alone. Moreover, the mechanisms by which PEG600 and PEG6000 enhance enzyme digestion were extensively examined using circular dichroism and fluorescence spectroscopy. The results from CD and fluorescence analyses indicated that PEG alters the protein conformation, thereby affecting the catalytic effect of the enzyme. Moreover, PEG improved the affinity between HiC and PET by lowering the surface tension of the solution, substantially enhancing PET hydrolysis. This study suggests that PEG holds considerable promise as an enzyme protector, significantly aiding in the hydrophilic modification and degradation of PET in an environmentally friendly and sustainable manner.
为了提高高度定向和结晶的聚对苯二甲酸乙二醇酯（PET）的酶解消化率，使用了不同分子量的聚乙二醇（PEG）表面活性剂来提高来自嗜热毁丝霉（Humicola insolens）的突变角质酶（HiC）的稳定性，并增加酶与底物的可及性。利用 HiC 水解 PET 的最佳条件，引入 1%w/v 的 PEG 可显著提高 PET 水解产物的产率。PEG600 的效果尤为显著，与单独使用 HiC 相比，产率提高了 64.58%。此外，还使用圆二色性和荧光光谱法广泛研究了 PEG600 和 PEG6000 增强酶消化的机制。CD 和荧光分析的结果表明，PEG 改变了蛋白质构象，从而影响了酶的催化效果。此外，PEG 通过降低溶液的表面张力提高了 HiC 和 PET 之间的亲和力，从而大大增强了 PET 的水解。这项研究表明，PEG 作为一种酶保护剂具有很大的应用前景，可显著促进 PET 的亲水性修饰和环保可持续的降解。
