Laboratory of Plant Biochemistry, Department of Biochemistry, University of Maringá, 87020-900, PR, Brazil.
Laboratory of Structural Biochemistry, Department of Technology, University of Maringá, Umuarama, 87506-370, PR, Brazil.
Plant Physiol Biochem. 2020 Jun;151:421-428. doi: 10.1016/j.plaphy.2020.03.053. Epub 2020 Apr 3.
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.
咖啡酰 3-O-甲基转移酶（COMT）催化咖啡酸的 3-羟基甲基化，生成阿魏酸，这是木质素生物合成的重要前体。木质素作为生物燃料生产的一个关键缺陷，限制了多糖的酶解，导致可发酵糖的产生。我们假设，对玉米 COMT 的控制抑制可能是一种有效的方法，可以减少阿魏酸和木质素，从而改善糖化过程。首先，我们应用计算机技术来预测玉米 COMT 的潜在抑制剂，选择了硝卡酚 entacapone。其次，体外实验证实了 entacapone 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的含量，增加了茎（18%）和叶（70%）的糖化，而不影响玉米的生长和木质素的生物合成。这种非基因修饰的方法可以作为一种替代策略，促进生物量多糖的酶解，提高生物乙醇生产的糖化率。
