Enhanced Activity of Enzymes Encapsulated in Hydrophilic Metal–Organic Frameworks

Abstract

Encapsulation of biomacromolecules in metal− organic frameworks (MOFs) can preserve biological functionality in harsh environments. Despite the success of this approach, termed biomimietic mineralization, limited consideration has been given to the chemistry of the MOF coating. Here, we show that enzymes encapsulated within hydrophilic MAF-7 or ZIF-90 retain enzymatic activity upon encapsulation and when exposed to high temperatures, denaturing or proteolytic agents, and organic solvents, whereas hydrophobic ZIF-8 affords inactive catalase and negligible protection to urease.

Modulating the Biofunctionality of Metal–Organic‐Framework‐Encapsulated Enzymes through Controllable Embedding Patterns

“…[23][24][25] However,t hese initial studies mainly focused on embedding functional enzymes in protective MOF cages without emphasizing the embedding patterns,a nd only limited consideration has been given to the conversion of the enzymatic biofunctionality after entrapment by aMOFs.This is worthy of attention, as the de novo encapsulating process could result in inactivation of enzymes due to their fragile nature.Indeed, we noticed that in some cases the enzymes are partially or even completely inactive when encapsulated within zeolitic imidazolate framework-8 (ZIF-8) crystals (see below), aw idely used exoskeleton for in situ enzyme encapsulation. [10,11,[14][15][16][17][18][19][20][21][22][23][24][25][26] In this work, we sought to reveal how embedding patterns influence the biofunctionality of enzymes encapsulated within ZIF-8 and to develop an ew strategy to produce enzymes@ZIF-8 biocomposites that maintain high enzymatic activity.W ec hose six typical enzymes as models, glucose oxidase (GOx), cytochrome C( Cyt C), horseradish peroxidase (HRP), catalase (CAT), urate oxidase (UOx) and alcohol dehydrogenase (ADH). These enzymes are extremely valuable across aw ide range of industries,i ncluding biofuel, food, and biosensing, and as therapeutics in the pharmaceutical industry.O ur findings show that ZIF-8-embedded enzymes (enzymes@ZIF-8), wherein the enzymes were encapsulated through rapid self-triggered nucleation around their surface,maintain high enzymatic activity,comparable to the free enzymes.I nt he other encapsulation process,w here the MOF nucleated as they normally would in the absence of the enzymes,a nd the enzymes were encapsulated through slow coprecipitation, the obtained enzymes@ZIF-8 tended to be inactive due to unfolding effects and competing coordination caused by the 2-methyl imidazole (HmIM) ligand.…”

Encapsulation, Visualization and Expression of Genes with Biomimetically Mineralized Zeolitic Imidazolate Framework‐8 (ZIF‐8)

“…For the synthesis of DNA encapsulated ZIF‐8 (DNA@ZIF‐8), the process of biomimetic mineralization was followed according to the protocol published by Liang et al, in which the presence of the biomolecule triggers in the formation of Zn(2mIM) 2 . The effect of the plGFP as a biomimetic mineralization agent was tested using Small‐Angle X‐ray Scattering at Elettra synchrotron; using a stop‐flow setup, the rapid formation of Zn(2mIM) 2 particles in presence of DNA was confirmed (Figure S1–S3, Supporting Information) and the bio‐composites were termed plGFP@ZIF‐8. Encapsulation of DNA within ZIF‐8 was visualized using a readily available DNA dye, propidium iodide (PI), which is a fluorescent DNA stain commonly used in laboratories for staining cellular DNA .…”

A novel semi‐dry method for the simultaneous removal of Hg and SO2 using spray drying absorption method

“…Hg 0 was oxidized to Hg 2+ , and then such chemical reduction between Hg 2+ and HSO 3 − occurred, which resulted in Hg 0 re‐emission from the reaction tower: …”