Wallace Paal W, Haernvall Karolina, Ribitsch Doris, Zitzenbacher Sabine, Schittmayer Matthias, Steinkellner Georg, Gruber Karl, Guebitz Georg M, Birner-Gruenberger Ruth
Research Unit for Functional Proteomics and Metabolic Pathways, Institute of Pathology, Medical University of Graz, Stiftingtalstrasse 24, 8010, Graz, Austria.
Austrian Centre of Industrial Biotechnology, Petersgasse 14, 8010, Graz, Austria.
Appl Microbiol Biotechnol. 2017 Mar;101(6):2291-2303. doi: 10.1007/s00253-016-7992-8. Epub 2016 Nov 21.
A novel esterase, PpEst, that hydrolyses the co-aromatic-aliphatic polyester poly(1,4-butylene adipate-co-terephthalate) (PBAT) was identified by proteomic screening of the Pseudomonas pseudoalcaligenes secretome. PpEst was induced by the presence of PBAT in the growth media and had predicted arylesterase (EC 3.1.1.2) activity. PpEst showed polyesterase activity on both whole and milled PBAT film releasing terephthalic acid and 4-(4-hydroxybutoxycarbonyl)benzoic acid while end product inhibition by 4-(4-hydroxybutoxycarbonyl)benzoic acid was observed. Modelling of an aromatic polyester mimicking oligomer into the PpEst active site indicated that the binding pocket could be big enough to accommodate large polymers. This is the first report of a PBAT degrading enzyme being identified by proteomic screening and shows that this approach can contribute to the discovery of new polymer hydrolysing enzymes. Moreover, these results indicate that arylesterases could be an interesting enzyme class for identifications of polyesterases.
通过对类产碱假单胞菌分泌组进行蛋白质组学筛选,鉴定出一种新型酯酶PpEst,它能水解共芳族 - 脂肪族聚酯聚(1,4 - 丁二醇己二酸酯 - 对苯二甲酸酯)(PBAT)。PpEst在生长培养基中PBAT存在时被诱导产生,并具有预测的芳基酯酶(EC 3.1.1.2)活性。PpEst对完整和研磨的PBAT薄膜均表现出聚酯酶活性,释放出对苯二甲酸和4 - (4 - 羟基丁氧基羰基)苯甲酸,同时观察到4 - (4 - 羟基丁氧基羰基)苯甲酸的终产物抑制作用。将一种模拟芳香族聚酯的低聚物建模到PpEst活性位点表明,结合口袋可能足够大以容纳大的聚合物。这是首次通过蛋白质组学筛选鉴定出PBAT降解酶的报告,表明该方法有助于发现新的聚合物水解酶。此外,这些结果表明芳基酯酶可能是用于鉴定聚酯酶的一类有趣的酶。