PHP-Family Diesterase from Novosphingobium with Broad Specificity and High Catalytic Efficiency against Organophosphate Flame-Retardant Derived Diesters.

IF 2.9 3区 生物学 Q3 BIOCHEMISTRY & MOLECULAR BIOLOGY
Biochemistry Biochemistry Pub Date : 2024-12-17 Epub Date: 2024-12-02 DOI:10.1021/acs.biochem.4c00350
Preston Garner, Andrew C Davis, Andrew N Bigley
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引用次数: 0

Abstract

Organophosphate flame retardants have been widely used in plastic products since the early 2000s. Unfortunately, these compounds leach out of the plastics over time and are carcinogenic, developmental toxins, and endocrine disruptors. Due to the high usage levels and stable nature of the compounds, widespread contamination of the environment has now been observed. Despite their recent introduction into the environment, bacteria from the Sphingomonadaceae family have evolved a three-step hydrolytic pathway to utilize these compounds. The second step in this pathway in Sphingobium sp. TCM1 is catalyzed by Sb-PDE, which is a member of the polymerase and histidinol phosphatase (PHP) family of phosphatases. This enzyme is only the second case of a PHP-family enzyme capable of hydrolyzing phosphodiesters. Bioinformatics analysis has now been used to identify a second PHP diesterase from Novosphingobium sp. EMRT-2 (No-PDE). Kinetic characterization of Sb-PDE and No-PDE with authentic organophosphate flame-retardant diesters demonstrates that these enzymes are true diesterases with more than 1000-fold selectivity for the diesterase activity seen in some cases. Synthesis of a wide array of authentic flame-retardant diesters has allowed the substrate specificity of these enzymes to be determined, and mutagenic analysis of the active site residues has identified key residues that give rise to the high levels of diesterase activity. Despite high sequence identity, No-PDE is found to have a broader substrate specificity against flame-retardant derived diesters, and kcat/Km values greater than 104 M-1 s-1 are seen with the best substrates.

新藻ph -家族二酯酶对有机磷阻燃衍生二酯具有广泛特异性和高催化效率。
自21世纪初以来,有机磷阻燃剂在塑料制品中得到了广泛的应用。不幸的是,随着时间的推移,这些化合物会从塑料中滤出,是致癌物质、发育毒素和内分泌干扰物。由于这些化合物的高使用量和稳定性,现已观察到对环境的广泛污染。尽管它们最近才被引入环境,但鞘单菌科的细菌已经进化出了一个三步水解途径来利用这些化合物。在Sphingobium sp. TCM1中,该途径的第二步是由Sb-PDE催化的,Sb-PDE是聚合酶和组氨酸二醇磷酸酶(PHP)家族的成员。这种酶是php家族中第二个能够水解磷酸二酯的酶。生物信息学分析现已用于从Novosphingobium sp. EMRT-2 (No-PDE)中鉴定第二种PHP二酯酶。Sb-PDE和No-PDE与真正的有机磷阻燃二酯的动力学表征表明,这些酶是真正的二酯酶,在某些情况下对二酯酶活性的选择性超过1000倍。大量真实的阻燃二酯的合成使得这些酶的底物特异性得以确定,活性位点残基的诱变分析已经确定了导致高水平二酯酶活性的关键残基。尽管具有较高的序列一致性,No-PDE对阻燃衍生二酯具有更广泛的底物特异性,最好的底物的kcat/Km值大于104 M-1 s-1。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
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来源期刊
Biochemistry Biochemistry
Biochemistry Biochemistry 生物-生化与分子生物学
CiteScore
5.50
自引率
3.40%
发文量
336
审稿时长
1-2 weeks
期刊介绍: Biochemistry provides an international forum for publishing exceptional, rigorous, high-impact research across all of biological chemistry. This broad scope includes studies on the chemical, physical, mechanistic, and/or structural basis of biological or cell function, and encompasses the fields of chemical biology, synthetic biology, disease biology, cell biology, nucleic acid biology, neuroscience, structural biology, and biophysics. In addition to traditional Research Articles, Biochemistry also publishes Communications, Viewpoints, and Perspectives, as well as From the Bench articles that report new methods of particular interest to the biological chemistry community.
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