PDF(Pubmed)
Abstract：
Carboxylic ester hydrolases with the capacity to degrade polyesters are currently highly sought after for their potential use in the biological degradation of PET and other chemically synthesized polymers. Here, we describe MarCE, a carboxylesterase family protein identified via genome mining of a Maribacter sp. isolate from the marine sponge Stelligera stuposa. Based on phylogenetic analysis, MarCE and its closest relatives belong to marine-associated genera from the Cytophaga-Flavobacterium-Bacteroides taxonomic group and appear evolutionarily distinct to any homologous carboxylesterases that have been studied to date in terms of structure or function. Molecular docking revealed putative binding of BHET, a short-chain PET derivative, onto the predicted MarCE three-dimensional structure. The synthetic ester-degrading activity of MarCE was subsequently confirmed by MarCE-mediated hydrolysis of 2 mM BHET substrate, indicated by the release of its breakdown products MHET and TPA, which were measured, respectively, as 1.28 and 0.12 mM following 2-h incubation at 30°C. The findings of this study provide further insight into marine carboxylic ester hydrolases, which have the potential to display unique functional plasticity resulting from their adaptation to complex and fluctuating marine environmentsw.
摘要：
具有降解聚酯的能力的羧酸酯水解酶目前因其在PET和其它化学合成聚合物的生物降解中的潜在用途而备受追捧。这里,我们描述MarCE,通过Maribactersp的基因组挖掘鉴定的羧酸酯酶家族蛋白。从海洋海绵Stelligerastuposa中分离出来。根据系统发育分析，MarCE及其近亲属于Cytophaga-黄杆菌-拟杆菌分类群的海洋相关属，在进化上与迄今为止在结构或功能方面研究的任何同源羧酸酯酶不同。分子对接揭示了BHET的推定结合，短链PET衍生物，到预测的MarCE三维结构上。随后通过MarCE介导的2mMBHET底物的水解证实了MarCE的合成酯降解活性，其细分产品MHET和TPA的发布表明，被测量的，分别,在30°C下孵育2小时后为1.28和0.12mM。这项研究的结果为海洋羧酸酯水解酶提供了进一步的见解，由于适应复杂和波动的海洋环境，它们有可能显示出独特的功能可塑性。
