Department of Analytical Chemistry, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden.
Biosens Bioelectron. 2010 Mar 15;25(7):1710-6. doi: 10.1016/j.bios.2009.12.017. Epub 2009 Dec 23.
A highly efficient anode for glucose biofuel cells has been developed by a combination of pyranose dehydrogenase from Agaricus meleagris (AmPDH) and cellobiose dehydrogenase from Myriococcum thermophilum (MtCDH). These two enzymes differ in how they oxidize glucose. AmPDH oxidizes glucose at the C(2) and C(3) carbon, whereas MtCDH at the C(1) carbon. Both enzymes oxidize efficiently a number of other mono- and disaccharides. They do not react directly with oxygen and produce no H(2)O(2). Electrodes were prepared by embedding (i) only AmPDH (in order to study this enzyme separately) and (ii) a mixture of AmPDH and MtCDH in an Os redox polymer hydrogel. Single-walled carbon nanotubes (SWCNTs) were added in order to enhance the current density. The electrodes were investigated with linear sweep and cyclic voltammetry in the presence of different substrates at physiological conditions. The electrochemical measurements revealed that the product of one enzyme can serve as a substrate for the other. In addition, a kinetic pathway analysis was performed by spectrophotometric measurements leading to the conclusion that up to six electrons can be gained from one glucose molecule through a combination of AmPDH and MtCDH. Hence, the combination of redox enzymes can lead to an enzymatic biofuel cell anode with an increased coulombic efficiency far beyond the usual yields of two electrons per substrate molecule.
一种高效的葡萄糖生物燃料电池阳极是通过将蜜环菌（Myriococcum thermophilum）来源的纤维二糖脱氢酶（MtCDH）和金针菇（Agaricus meleagris）来源的吡喃糖脱氢酶（AmPDH）相结合而开发的。这两种酶在氧化葡萄糖的方式上有所不同。AmPDH 在 C(2)和 C(3)碳原子上氧化葡萄糖，而 MtCDH 在 C(1)碳原子上氧化葡萄糖。这两种酶都能有效地氧化许多其他单糖和二糖。它们不与氧气直接反应，也不会产生 H(2)O(2)。通过将（i）仅 AmPDH（为了单独研究这种酶）和（ii）AmPDH 和 MtCDH 的混合物嵌入到 Os 氧化还原聚合物水凝胶中来制备电极。添加单壁碳纳米管（SWCNTs）以提高电流密度。在生理条件下，通过线性扫描和循环伏安法在存在不同底物的情况下研究了这些电极。电化学测量表明，一种酶的产物可以作为另一种酶的底物。此外，通过分光光度法进行了动力学途径分析，得出结论，通过 AmPDH 和 MtCDH 的组合，可以从一个葡萄糖分子中获得多达六个电子。因此，氧化还原酶的组合可以导致酶生物燃料电池阳极的库仑效率大大提高，远远超过通常每底物分子两个电子的产率。
