美国德克萨斯大学奥斯汀分校Hal S. Alper研究小组近日取得一项新成果。经过不懈努力，他们利用机器辅助学习工具设计了聚对苯二甲酸乙二醇酯 (PET)解聚水解酶。2022年4月27日，国际学术期刊《自然》发表了这一成果。
研究人员使用基于结构的机器学习算法设计了高效且活跃的PET水解酶。研究人员设计的突变体和支架组合（FAST-PETase：功能性、活性、稳定和耐受性 PETase）与野生型PETase相比包含五个突变（来自预测蛋白的N233K/R224Q/S121E和来自支架蛋白的D186H/R280A）；FAST-PETase与野生型和工程替代品相比显示出优异的PET水解活性，可在30 或50°C以及一系列 pH 值之间发挥功能。研究证明，FAST-PETase几乎可以在一周内完全讲解51种不同热成型未经处理的PET废弃物。
FAST-PETase还可以在50 ºC下解聚商业水瓶和无法进行热预处理的无定形部分。最后，通过使用FAST-PETase并利用回收单体重新合成PET，研究人员展示了一个闭环PET回收过程。总的来说，该研究结果提出了一种在工业规模上进行酶塑料回收的可行途径。
据悉，塑料污染对生态环境产生了挑战，酶降解为聚酯废物回收提供了一种潜在的绿色、可扩展途径。PET占全球固体废物的12%，PET碳循环经济理论上可以通过快速酶解聚然后再聚合或转化/增值为其他产品来实现。然而，PET水解酶的应用受到阻碍，因为它们对pH和温度范围具有依赖性、反应速度慢以及无法直接降解未经处理的消费后塑料。
附：英文原文
Title: Machine learning-aided engineering of hydrolases for PET depolymerization
Author: Lu, Hongyuan, Diaz, Daniel J., Czarnecki, Natalie J., Zhu, Congzhi, Kim, Wantae, Shroff, Raghav, Acosta, Daniel J., Alexander, Bradley R., Cole, Hannah O., Zhang, Yan, Lynd, Nathaniel A., Ellington, Andrew D., Alper, Hal S.
Issue&Volume: 2022-04-27
Abstract: Plastic waste poses an ecological challenge1,2,3 and enzymatic degradation offers one, potentially green and scalable, route for polyesters waste recycling4. Poly(ethylene terephthalate) (PET) accounts for 12% of global solid waste5, and a circular carbon economy for PET is theoretically attainable through rapid enzymatic depolymerization followed by repolymerization or conversion/valorization into other products6,7,8,9,10. Application of PET hydrolases, however, has been hampered by their lack of robustness to pH and temperature ranges, slow reaction rates and inability to directly use untreated postconsumer plastics11. Here, we use a structure-based, machine learning algorithm to engineer a robust and active PET hydrolase. Our mutant and scaffold combination (FAST-PETase: functional, active, stable and tolerant PETase) contains five mutations compared to wild-type PETase (N233K/R224Q/S121E from prediction and D186H/R280A from scaffold) and shows superior PET-hydrolytic activity relative to both wild-type and engineered alternatives12 between 30 and 50°C and a range of pH levels. We demonstrate that untreated, postconsumer-PET from 51 different thermoformed products can all be almost completely degraded by FAST-PETase in 1week. FAST-PETase can also depolymerize untreated, amorphous portions of a commercial water bottle and an entire thermally pretreated water bottle at 50oC. Finally, we demonstrate a closed-loop PET recycling process by using FAST-PETase and resynthesizing PET from the recovered monomers. Collectively, our results demonstrate a viable route for enzymatic plastic recycling at the industrial scale.
DOI: 10.1038/s41586-022-04599-z
Source: https://www.nature.com/articles/s41586-022-04599-z
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
