Bilirubin oxidase from Myrothecium verrucaria (mBOD) is a promising enzyme for catalyzing the four-electron reduction of dioxygen into water and realizes direct electron transfer (DET)-type bioelectrocatalysis. It has two N-linked glycans (N-glycans), and N472 and N482 are known as binding sites. Both binding sites located on opposite side of the type I (T1) Cu, which is the electrode-active site of BOD. We investigated the effect of N-glycans on DET-type bioelectrocatalysis by performing electrochemical measurements using electrodes with controlled surface charges. Two types of BODs with different N-glycans, mBOD and recombinant BOD overexpressed in Pichia pastoris (pBOD), and their deglycosylated forms (dg-mBOD and dg-pBOD) were used in this study. Kinetic analysis of the steady-state catalytic waves revealed that both size and composition of N-glycans affected the orientation of adsorbed BODs on the electrodes. Interestingly, the most favorable orientation was achieved with pBOD, which has the largest N-glycans. Furthermore, the effect of the orientation control by the N-glycans is cooperative with electrostatic interaction.

来自Myrothecium v​​errucaria (mBOD) 的胆红素氧化酶是一种很有前途的酶，用于催化双氧四电子还原成水，并实现直接电子转移 (DET) 型生物电催化。它有两个N-连接聚糖 ( N -glycans)，N472 和 N482 被称为结合位点。两个结合位点都位于 I 型 (T1) Cu 的另一侧，这是 BOD 的电极活性位点。我们通过使用具有受控表面电荷的电极进行电化学测量，研究了N-聚糖对 DET 型生物电催化的影响。具有不同N-聚糖的两种类型的BOD，mBOD 和在毕赤酵母中过表达的重组 BOD(pBOD) 及其去糖基化形式（dg-mBOD 和 dg-pBOD）用于本研究。稳态催化波的动力学分析表明，N-聚糖的大小和组成都会影响吸附在电极上的 BOD 的方向。有趣的是，最有利的方向是用 pBOD 实现的，它具有最大的N-聚糖。此外，N-聚糖的定向控制效果与静电相互作用协同作用。