Lytic polysaccharide monooxygenases (LPMOs) have emerged as key proteins for depolymerization of cellulose. These copper-containing enzymes oxidize C-1 and/or C-4 bonds in cellulose, promoting increased hydrolysis of the oxidized cellulose chains. The LPMO from Thermoascus aurantiacus, a thermophilic ascomycete fungus, has been extensively studied and has served as a model LPMO. A method was developed to purify the LPMO from culture filtrates of T. aurantiacus along with its native cellobiohydrolase and endoglucanase. The activity of the purified LPMO was measured with a colorimetric assay that established the Topt of the native LPMO at 60 °C. Purification of the components of the T. aurantiacus cellulase mixture also enabled quantification of the amounts of cellobiohydrolase, endoglucanase and LPMO present in the T. aurantiacus culture filtrate, establishing that the LPMO was the most abundant protein in the culture supernatants. The importance of the LPMO to activity of the mixture was demonstrated by saccharifications with Avicel and acid-pretreated corn stover.

中文翻译：

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橘色嗜热子囊菌天然裂解多糖单加氧酶的纯化和表征

裂解多糖单加氧酶 (LPMO) 已成为纤维素解聚的关键蛋白质。这些含铜酶氧化纤维素中的 C-1 和/或 C-4 键，促进氧化纤维素链的水解增加。来自嗜热子囊菌真菌 Thermoascus aurantiacus 的 LPMO 已被广泛研究并用作模型 LPMO。开发了一种方法来从 T. aurantiacus 的培养滤液中纯化 LPMO 及其天然纤维二糖水解酶和内切葡聚糖酶。使用比色测定法测量纯化 LPMO 的活性，该测定法在 60 °C 下建立了天然 LPMO 的 Topt。T. aurantiacus 纤维素酶混合物成分的纯化还能够量化 T. aurantiacus 培养滤液中存在的纤维二糖水解酶、内切葡聚糖酶和 LPMO 的量，确定 LPMO 是培养上清液中最丰富的蛋白质。LPMO 对混合物活性的重要性通过 Avicel 和酸预处理玉米秸秆的糖化得到证明。