Preparation of ZIF@ADH/NAD-MSN/LDH Core Shell Nanocomposites for the Enhancement of Coenzyme Catalyzed Double Enzyme Cascade

Abstract

The field of enzyme cascades in limited microscale or nanoscale environments has undergone a quick growth and attracted increasing interests in the field of rapid development of systems chemistry. In this study, alcohol dehydrogenase (ADH), lactate dehydrogenase (LDH), and mesoporous silica nanoparticles (MSN) immobilized nicotinamide adenine dinucleotide (NAD+) were successfully immobilized on the zeolitic imidazolate frameworks (ZIFs). This immobilized product was named ZIF@ADH/NAD-MSN/LDH, and the effect of the multi-enzyme cascade was studied by measuring the catalytic synthesis of lactic acid. The loading efficiency of the enzyme in the in-situ co-immobilization method reached 92.65%. The synthesis rate of lactic acid was increased to 70.10%, which was about 2.82 times that of the free enzyme under the optimal conditions (40 °C, pH = 8). Additionally, ZIF@ADH/NAD-MSN/LDH had experimental stability (71.67% relative activity after four experiments) and storage stability (93.45% relative activity after three weeks of storage at 4 °C; 76.89% relative activity after incubation in acetonitrile-aqueous solution for 1 h; 27.42% relative activity after incubation in 15% N, N-Dimethylformamide (DMF) solution for 1 h). In summary, in this paper, the cyclic regeneration of coenzymes was achieved, and the reaction efficiency of the multi-enzyme biocatalytic cascade was improved due to the reduction of substrate diffusion.

Rhodium-Based MOF-on-MOF Difunctional Core–Shell Nanoreactor for NAD(P)H Regeneration and Enzyme Directed Immobilization

“…Noticeably, the conversion rate of UiO67@Rh@UiO66@LDH was 1.5 times that of free LDH. Due to its low stability, free LDH was rapidly inactivated, which also highlighted the advantages of immobilized enzymes. − The coupling between NADH regeneration and LDH exhibited great potential for sustainable lactate production. To demonstrate the effect of substrate diffusion distance on the conversion rate, UiO67@Rh@UiO66 and an equal concentration of free LDH-catalyzed pyruvate reduction in the same system.…”

Enzymatic Electrochemical/Fluorescent Nanobiosensor for Detection of Small Chemicals

“…For instance, enzymes, such as peroxidase and catalase, can be used to catalyze the oxidation of various substrates using H 2 O 2 as a co-substrate, producing detectable signals, such as color changes or oxygen gas bubbles [ 50 ]. Similarly, enzymes, such as alcohol dehydrogenase and lactate dehydrogenase, can be used to catalyze redox reactions with coenzymes, such as NAD+ and NADH, which can be measured electrochemically or optically [ 51 ]. In such reactions, the enzyme facilitates the transfer of electrons between the substrate and the coenzyme, resulting in a change in the redox state of the coenzyme that can be detected.…”

3D Visualization of Proteins within Metal–Organic Frameworks via Ferritin‐Enabled Electron Microscopy

“…[8,12,15,16] The prevailing methods to assess protein spatial distribution in protein@MOFs involve indirect studies conducted after thermal calcination [17,18] or confocal laser scanning microscopy (CLSM) paired with fluorescent protein labeling. [7,15,[19][20][21][22][23][24][25] Although CLSM is a powerful tool for evaluating the overall protein spatial distribution, its spatial resolution is limited, and protein modifications can impact their localization. [15,26] Transmission electron microscopy (TEM) is a widely employed technique for examining the crystallinity, dynamics, and composition of MOFs with high spatial resolution.…”