Coccia Francesca, Tonucci Lucia, Del Boccio Piero, Caporali Stefano, Hollmann Frank, d'Alessandro Nicola
Department of Engineering and Geology (INGEO), G. d'Annunzio University of Chieti-Pescara, Viale Pindaro 42, I-66100 Chieti Scalo, Italy.
Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629HZ Delft, The Netherlands.
Nanomaterials (Basel). 2018 Oct 19;8(10):853. doi: 10.3390/nano8100853.
The combination of metal nanoparticles (Pd or Pt NPs) with NAD-dependent thermostable alcohol dehydrogenase (TADH) resulted in the one-flask catalytic double reduction of 3-methyl-2-cyclohexenone to 3-(1S,3S)-methylcyclohexanol. In this article, some assumptions about the interactions between a chemocatalyst and a biocatalyst have been proposed. It was demonstrated that the size of the NPs was the critical parameter for the mutual inhibition: the bigger the NPs, the more harmful for the enzyme they were, even if the NPs themselves were only moderately inactivated. Conversely, the smaller the NPs, the more minimal the TADH denaturation, although they were dramatically inhibited. Resuming, the chemocatalysts were very sensitive to deactivation, which was not related to the amount of enzyme used, while the inhibition of the biocatalyst can be strongly reduced by minimizing the NPs/TADH ratio used to catalyze the reaction. Among some methods to avoid direct binding of NPs with TADH, we found that using large Pd NPs and protecting their surfaces with a silica shell, the overall yield of 3-(1S,3S)-methylcyclohexanol was maximized (36%).
金属纳米颗粒（钯或铂纳米颗粒）与依赖烟酰胺腺嘌呤二核苷酸的耐热醇脱氢酶（TADH）相结合，实现了在单瓶中将3-甲基-2-环己烯酮一步催化双还原为3-(1S,3S)-甲基环己醇。在本文中，提出了一些关于化学催化剂与生物催化剂之间相互作用的假设。结果表明，纳米颗粒的尺寸是相互抑制的关键参数：纳米颗粒越大，对酶的危害就越大，即使纳米颗粒本身只是适度失活。相反，纳米颗粒越小，TADH变性程度越低，尽管它们受到显著抑制。总之，化学催化剂对失活非常敏感，这与所用酶的量无关，而通过最小化用于催化反应的纳米颗粒/TADH比例，可以大大降低对生物催化剂的抑制作用。在一些避免纳米颗粒与TADH直接结合的方法中，我们发现使用大尺寸的钯纳米颗粒并用二氧化硅壳保护其表面，可以使3-(1S,3S)-甲基环己醇的总产率最大化（36%）。
