Oxidative Cleavage of Cellulose by Fungal Copper-Dependent Polysaccharide Monooxygenases

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• 作者：William T. Beeson ; Christopher M. Phillips ; Jamie H. D. Cate ; Michael A. Marletta
• 刊名：The Journal of the American Chemical Society
• 出版年：2012
• 出版时间：January 18, 2012
• 年：2012
• 卷：134
• 期：2
• 页码：890-892
• 全文大小：231K
• 年卷期：v.134,no.2(January 18, 2012)
• ISSN：1520-5126

文摘

Fungal-derived, copper-dependent polysaccharide monooxygenases (PMOs), formerly known as GH61 proteins, have recently been shown to catalyze the O₂-dependent oxidative cleavage of recalcitrant polysaccharides. Different PMOs isolated from Neurospora crassa were found to generate oxidized cellodextrins modified at the reducing or nonreducing ends upon incubation with cellulose and cellobiose dehydrogenase. Here we show that the nonreducing end product formed by an N. crassa PMO is a 4-ketoaldose. Together with isotope labeling experiments, further support is provided for a mechanism involving oxygen insertion and subsequent elimination to break glycosidic bonds in crystalline cellulose.