Caffeate 3-O-methyltransferase (COMT) catalyzes the methylation of the 3-hydroxyl group of caffeate to produce ferulate, an important precursor of the lignin biosynthesis. As a crucial drawback for biofuel production, lignin limits the enzymatic hydrolysis of polysaccharides to result in fermentable sugars. We hypothesized that a controlled inhibition of maize COMT can be an efficient approach to reduce ferulate and lignin, thus improving the saccharification process. First, we applied in silico techniques to prospect potential inhibitors of ZmaysCOMT, and the nitrocatechol entacapone was selected. Second, in vitro assays confirmed the inhibitory effect of entacapone on maize COMT. Finally, in vivo experiments revealed that entacapone reduced the contents of cell-wall-esterified hydroxycinnamates and increased saccharification of stems (18%) and leaves (70%), without negatively affecting maize growth and lignin biosynthesis. This non-genetically modified approach can be an alternative strategy to facilitate the enzymatic hydrolysis of biomass polysaccharides and increase saccharification for bioethanol production.

中文翻译：

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恩他卡朋在不影响木质素和玉米生长的情况下改善糖化作用：计算机，体外和体内方法。

咖啡因3-O-甲基转移酶（COMT）催化咖啡因的3-羟基甲基化以生成阿魏酸，阿魏酸是木质素生物合成的重要前体。作为生物燃料生产的关键缺点，木质素限制了多糖的酶促水解，从而产生可发酵的糖。我们假设对玉米COMT的受控抑制可以是减少阿魏酸和木质素从而改善糖化过程的有效方法。首先，我们将计算机技术应用于潜在的ZmaysCOMT抑制剂，然后选择了硝基邻苯二酚他他酮。其次，体外测定证实了恩他卡朋对玉米COMT的抑制作用。最后，体内实验表明，entacapone降低了细胞壁酯化羟基肉桂酸酯的含量，并增加了茎（18％）和叶片（70％）的糖化作用，而对玉米的生长和木质素的生物合成没有负面影响。这种非遗传修饰的方法可以作为一种替代策略，以促进生物质多糖的酶促水解并提高生物乙醇生产的糖化度。