The linker region of multi-domain enzymes has a very important role for the interconnection of different enzyme modules and for the efficiency of catalytic activity. This is particularly evident for artificial chimeric systems. We characterised an artificial self-sufficient enzyme developed by genetic fusion of the catalytic domain of cytochrome P450 3A4 and reductase domain of Bacillus megaterium BM3 (BMR).

Here we report the direct electrochemistry of 3A4-BMR chimeras immobilised on glassy carbon electrodes and we investigated the effect of inter-domain loop length and immobilising environment flexibility on both redox properties and electrocatalysis. We observe that redox potential can be modulated by the linker length and the immobilising layer flexibility. In addition, enzyme inter-domain dynamics and environment flexibility also modulate 3A4-BMR turnover efficiency on electrode system. V_max values are increased up to about 100% in the presence of testosterone and up to about 50% in presence of tamoxifen by decreasing immobilising film rigidity. The effect on 3A4-BMR V_max values is dependent on inter-domain loop length with 3A4-5GLY-BMR chimera being the more affected. The underlying reason for these observations is the potential motion of the FMN domain that is the key to shuttle electrons from FAD to haem.

多域酶的接头区域对于不同酶模块的互连以及催化活性的效率具有非常重要的作用。这对于人工嵌合系统特别明显。我们表征了通过基因融合的细胞色素P450 3A4的催化域和巨大芽孢杆菌BM3（BMR）的还原酶域的遗传开发的人工自给自足的酶。

在这里，我们报告了固定在玻璃碳电极上的3A4-BMR嵌合体的直接电化学，并且我们研究了域间环长度和固定化环境柔性对氧化还原性质和电催化作用的影响。我们观察到，氧化还原电势可以通过接头长度和固定层的柔韧性进行调节。另外，酶的域间动力学和环境灵活性还调节电极系统上3A4-BMR的转换效率。通过降低固定膜的刚性，在睾丸酮存在下，V _max值增加至约100％，在他莫昔芬存在下增加至约50％。对3A4-BMR V _max的影响值取决于域间环长度，其中3A4-5GLY-BMR嵌合体受影响更大。这些观察的根本原因是FMN域的潜在运动，这是将电子从FAD传递到血红素的关键。