Unveiling the Enzymatic Pathway of UMG-SP2 Urethanase: Insights into Polyurethane Degradation at the Atomic Level

IF 7.6 1区 化学 Q1 CHEMISTRY, MULTIDISCIPLINARY
Pedro Paiva, Luís Miguel Correia Teixeira, Wei Ren, Weidong Liu, Gert Weber, Jens Preben Morth, Peter Westh, Allan R. Petersen, Martin Johansen, Andreas Sommerfeldt, Alexander Sandahl, Daniel Otzen, Pedro Alexandrino Fernandes, Maria Joao Joao Ramos
{"title":"Unveiling the Enzymatic Pathway of UMG-SP2 Urethanase: Insights into Polyurethane Degradation at the Atomic Level","authors":"Pedro Paiva, Luís Miguel Correia Teixeira, Wei Ren, Weidong Liu, Gert Weber, Jens Preben Morth, Peter Westh, Allan R. Petersen, Martin Johansen, Andreas Sommerfeldt, Alexander Sandahl, Daniel Otzen, Pedro Alexandrino Fernandes, Maria Joao Joao Ramos","doi":"10.1039/d4sc06688j","DOIUrl":null,"url":null,"abstract":"The recently discovered metagenomic urethanases UMG-SP1, UMG-SP2, and UMG-SP3 have emerged as promising tools to establish a bio-based recycling approach for polyurethane (PU) waste. These enzymes are capable of hydrolyzing urethane bonds in low molecular weight dicarbamates as well as in thermoplastic PU and the amide bond in polyamide employing a Ser-Sercis-Lys triad for catalysis, similar to members of the amidase signature protein superfamily. Understanding the catalytic mechanism of these urethanases is crucial for enhancing their enzymatic activity and improving PU bio-recycling processes. In this study, we employed hybrid quantum mechanics/molecular mechanics methods to delve into the catalytic machinery of the UMG-SP2 urethanase in breaking down a model PU substrate. Our results indicate that the reaction proceeds in two stages: STAGE 1 - acylation, in which the enzyme becomes covalently bound to the PU substrate, releasing an alcohol-leaving group; STAGE 2 - deacylation, in which a catalytic water hydrolyzes the enzyme:ligand covalent adduct, releasing the product in the form of a highly unstable carbamic acid, expected to rapidly decompose into an amine and carbon dioxide. We found that STAGE 1 comprises the rate-limiting step of the overall reaction, consisting of the cleavage of the substrate’s urethane bond by its ester moiety and the release of the alcohol-leaving group (overall Gibbs activation energy of 20.8 kcal·mol-1). Lastly, we identified point mutations that are expected to enhance the enzyme's turnover for the hydrolysis of urethane bonds by stabilizing the macrodipole of the rate-limiting transition state. These findings expand our current knowledge of urethanases and homolog enzymes from the amidase signature superfamily, paving the way for future research on improving the enzymatic depolymerization of PU plastic materials.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"56 1","pages":""},"PeriodicalIF":7.6000,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Science","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1039/d4sc06688j","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0

Abstract

The recently discovered metagenomic urethanases UMG-SP1, UMG-SP2, and UMG-SP3 have emerged as promising tools to establish a bio-based recycling approach for polyurethane (PU) waste. These enzymes are capable of hydrolyzing urethane bonds in low molecular weight dicarbamates as well as in thermoplastic PU and the amide bond in polyamide employing a Ser-Sercis-Lys triad for catalysis, similar to members of the amidase signature protein superfamily. Understanding the catalytic mechanism of these urethanases is crucial for enhancing their enzymatic activity and improving PU bio-recycling processes. In this study, we employed hybrid quantum mechanics/molecular mechanics methods to delve into the catalytic machinery of the UMG-SP2 urethanase in breaking down a model PU substrate. Our results indicate that the reaction proceeds in two stages: STAGE 1 - acylation, in which the enzyme becomes covalently bound to the PU substrate, releasing an alcohol-leaving group; STAGE 2 - deacylation, in which a catalytic water hydrolyzes the enzyme:ligand covalent adduct, releasing the product in the form of a highly unstable carbamic acid, expected to rapidly decompose into an amine and carbon dioxide. We found that STAGE 1 comprises the rate-limiting step of the overall reaction, consisting of the cleavage of the substrate’s urethane bond by its ester moiety and the release of the alcohol-leaving group (overall Gibbs activation energy of 20.8 kcal·mol-1). Lastly, we identified point mutations that are expected to enhance the enzyme's turnover for the hydrolysis of urethane bonds by stabilizing the macrodipole of the rate-limiting transition state. These findings expand our current knowledge of urethanases and homolog enzymes from the amidase signature superfamily, paving the way for future research on improving the enzymatic depolymerization of PU plastic materials.
求助全文
约1分钟内获得全文 求助全文
来源期刊
Chemical Science
Chemical Science CHEMISTRY, MULTIDISCIPLINARY-
CiteScore
14.40
自引率
4.80%
发文量
1352
审稿时长
2.1 months
期刊介绍: Chemical Science is a journal that encompasses various disciplines within the chemical sciences. Its scope includes publishing ground-breaking research with significant implications for its respective field, as well as appealing to a wider audience in related areas. To be considered for publication, articles must showcase innovative and original advances in their field of study and be presented in a manner that is understandable to scientists from diverse backgrounds. However, the journal generally does not publish highly specialized research.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信