Department of Chemical Engineering, Konkuk University, Seoul 05029, Republic of Korea.
Int J Mol Sci. 2024 Feb 27;25(5):2746. doi: 10.3390/ijms25052746.
Multi-enzymatic strategies have shown improvement in bioconversion during cofactor regeneration. In this study, purified l-arabinitol 4-dehydrogenase (LAD) and nicotinamide adenine dinucleotide oxidase (Nox) were immobilized via individual, mixed, and sequential co-immobilization approaches on magnetic nanoparticles, and were evaluated to enhance the conversion of l-arabinitol to l-xylulose. Initially, the immobilization of LAD or Nox on the nanoparticles resulted in a maximum immobilization yield and relative activity of 91.4% and 98.8%, respectively. The immobilized enzymes showed better pH and temperature profiles than the corresponding free enzymes. Furthermore, co-immobilization of these enzymes via mixed and sequential methods resulted in high loadings of 114 and 122 mg/g of support, respectively. Sequential co-immobilization of these enzymes proved more beneficial for higher conversion than mixed co-immobilization because of better retaining Nox residual activity. Sequentially co-immobilized enzymes showed a high relative conversion yield with broader pH, temperature, and storage stability profiles than the controls, along with high reusability. To the best of our knowledge, this is the first report on the mixed or sequential co-immobilization of LAD and Nox on magnetic nanoparticles for l-xylulose production. This finding suggests that selecting a sequential co-immobilization strategy is more beneficial than using individual or mixed co-immobilized enzymes on magnetic nanoparticles for enhancing conversion applications.
多酶策略已显示在共因子再生过程中的生物转化得到改善。在这项研究中,通过单独、混合和顺序共固定化方法将纯化的 L-阿拉伯糖醇 4-脱氢酶(LAD)和烟酰胺腺嘌呤二核苷酸氧化酶(Nox)固定在磁性纳米颗粒上,并对其进行评估以提高 L-阿拉伯糖醇转化为 L-木酮糖的效率。最初,LAD 或 Nox 在纳米颗粒上的固定化导致最大固定化产率和相对活性分别为 91.4%和 98.8%。固定化酶的 pH 和温度谱比相应的游离酶更好。此外,通过混合和顺序方法共固定化这些酶导致载体的高负载量分别为 114 和 122mg/g。由于更好地保留了 Nox 的残余活性,与混合共固定化相比,这些酶的顺序共固定化更有利于更高的转化率。顺序共固定化酶显示出比对照更高的相对转化率,具有更宽的 pH、温度和储存稳定性谱,以及高的可重复使用性。据我们所知,这是首次报道在磁性纳米颗粒上混合或顺序共固定化 LAD 和 Nox 用于生产 L-木酮糖。这一发现表明,与在磁性纳米颗粒上使用单独或混合的共固定化酶相比,选择顺序共固定化策略更有利于提高转化率。