Physical Chemistry Department and Institute of Electrochemistry, University of Alicante, 03080, Alicante, Spain.
CEMHTI, CNRS (UPR 3079) University of Orléans, 45071, Orléans, France.
Bioprocess Biosyst Eng. 2021 Aug;44(8):1699-1710. doi: 10.1007/s00449-021-02553-3. Epub 2021 Apr 3.
This study reports the immobilization of two biocatalysts (e.g., cytochrome c-Cyt c-and the non-metalloenzyme formate dehydrogenase from Candida boidinii-cbFDH) on a series of mesoporous carbons with controlled pore sizes. The catalytic activity of the nanoconfined proteins was correlated with the pore size distribution of the carbon materials used as supports. The electrochemical behaviour of nanoconfined Cyt c showed direct electron transfer electroactivity in pore sizes matching tightly the protein dimension. The pseudo-peroxidase activity towards HO reduction was enhanced at pH 4.0, due to the protein conformational changes. For cbFDH, the reduction of CO towards formic acid was evaluated for the nanoconfined protein, in the presence of nicotinamide adenine dinucleotide (NADH). The carbons displayed different cbFDH uptake capacity, governed by the dimensions of the main mesopore cavities and their accessibility through narrow pore necks. The catalytic activity of nanoconfined cbFDH was largely improved, compared to its performance in free solution. Regardless of the carbon support used, the production of formic acid was higher upon immobilization with lower nominal cbFDH:NADH ratios.
本研究报告了一系列具有受控孔径的中孔碳上两种生物催化剂（例如细胞色素 c-Cyt c 和来自 Candida boidinii 的非金属酶甲酸脱氢酶-cbFDH）的固定化。纳米限域蛋白质的催化活性与用作载体的碳材料的孔径分布相关。纳米限域 Cyt c 的电化学行为表现出与蛋白质尺寸紧密匹配的孔内直接电子转移电活性。在 pH 值为 4.0 时，由于蛋白质构象发生变化，HO 的还原表现出类过氧化物酶活性。对于 cbFDH，在烟酰胺腺嘌呤二核苷酸（NADH）存在下，评估了纳米限域蛋白对 CO 向甲酸的还原。碳显示出不同的 cbFDH 摄取能力，这取决于主要中孔腔的尺寸及其通过窄孔颈的可及性。与游离溶液中的性能相比，纳米限域 cbFDH 的催化活性得到了极大提高。无论使用哪种碳载体，固定化时使用较低的名义 cbFDH:NADH 比会导致甲酸的产量更高。
