Separate Enzymes Research Articles

Simultaneous separation and biocatalytic conversion of formaldehyde to methanol in enzymatic membrane reactor

Combination of the reaction simultaneously with separation inside a single process unit or commonly known as reactive separation technology is widely studied nowadays as it would give mutual benefits for both enzymatic catalysis and membrane separation process. Alcohol dehydrogenase (ADH) at 0.10 g/L (dissolved in 0.10 M Tris-HCl buffer) was immobilized on commercially available PES and PVDF membrane at pH 7 and TMP 2 bar by reverse filtration method. Then the immobilized enzyme was subjected to the biocatalytic conversion of formaldehyde to methanol. The immobilization process successfully immobilized 87.67% and 70.94% of ADH enzyme in/on the PVDF and PES membrane, respectively. The subsequent reaction was able to convert formaldehyde to methanol as high as 90% conversion and a high biocatalytic productivity of 460 µmol CH3OH/mgenzyme·h for PVDF membranes. Enzyme relative activity could be retained for at least seven consecutive cycles. This study suggested that immobilization of ADH on the polymer membrane can increase enzyme loading and also retain its activity for a simultaneous conversion and separation of formaldehyde to methanol.

New insights into amylose and amylopectin biosynthesis in rice endosperm

How various isoforms of rice-starch biosynthesis enzymes interact during amylose and amylopectin synthesis is explored. The chain-length distributions of amylopectin and amylose from 95 varieties with different environmental and genetic backgrounds were obtained using size- exclusion chromatography, and fitted with biosynthesis-derived models based on isoforms of starch synthase (SSI-SSIV), starch branching enzyme (SBE, including SBEI and SBEII) and granule-bound starch synthase (GBSS) that are involved in amylose and amylopectin synthesis. It is usually thought that these are synthesized by separate enzymes. However, the amount of longer amylopectin chains correlated with that of shorter amylose chains, indicating that GBSS, SBE and SS affect both amylose and amylopectin synthesis. Further, the activity of GBSS in amylose correlated with that of SS in amylopectin. This new understanding of which enzymes are suggested by the statistics to be involved in both amylose and amylopectin synthesis could help rice breeders develop cereals with targeted properties.

Electrical Field Reversibly Modulates Enzyme Kinetics of Hexokinase Entrapped in an Electro-Responsive Hydrogel.

In this paper, the potential use of electro-responsive poly(acrylic acid) (PAA) gels as reversible enzyme activity regulators is analyzed. This was evaluated by measuring the glucose conversion by hexokinase embedded PAA hydrogels under external electrical stimuli. Hexokinase physically entrapped within PAA gels showed a significant increase in activity under an electrical stimulus as compared to in the absence of a stimulus. Kinetic studies revealed that the change in reaction rate could be attributed to the change of Vmax under a stimulus, while Km was unaffected by the stimulus, which suggested that the increase in reaction rate under an electrical stimulus was due to increased accessibility of the active site. Optimum stimuli-responsive behavior that resulted in maximum conversion under a stimulus and minimum conversion in the absence of a stimulus was obtained at 5.5 pH and 30 °C. The significant difference between the pH optima for the entrapped enzyme and the pure enzyme can be attributed to the acidic nature of the polymeric matrix. Higher cross-linker concentrations resulted in a reduction of both enzyme release and glucose conversion, and a reasonable trade-off between conversion and release could be obtained at 5% cross-linker concentration. Application of a stepwise electrical stimulus revealed that the entrapped enzymes could sustain responsive properties over multiple cycles of electrical switching. Entrapped hexokinase also showed much better reusability compared to pure hexokinase, a combined result of higher enzyme retention and increased stability. No significant impact of the polymer on the interaction between enzyme and glucose was observed. Thus, this system enables electro-responsive modulation of enzyme activity without any reduction in enzyme activity. The studies revealed that conjugation of electro-responsive polymers to enzymes has the potential to reversibly modulate enzymatic reactions via the application of external electrical stimuli, which is promising for bioprocessing and enzymatic separation applications.

GDGT cyclization proteins identify the dominant archaeal sources of tetraether lipids in the ocean

Glycerol dibiphytanyl glycerol tetraethers (GDGTs) are distinctive archaeal membrane-spanning lipids with up to eight cyclopentane rings and/or one cyclohexane ring. The number of rings added to the GDGT core structure can vary as a function of environmental conditions, such as changes in growth temperature. This physiological response enables cyclic GDGTs preserved in sediments to be employed as proxies for reconstructing past global and regional temperatures and to provide fundamental insights into ancient climate variability. Yet, confidence in GDGT-based paleotemperature proxies is hindered by uncertainty concerning the archaeal communities contributing to GDGT pools in modern environments and ambiguity in the environmental and physiological factors that affect GDGT cyclization in extant archaea. To properly constrain these uncertainties, a comprehensive understanding of GDGT biosynthesis is required. Here, we identify 2 GDGT ring synthases, GrsA and GrsB, essential for GDGT ring formation in Sulfolobus acidocaldarius Both proteins are radical S-adenosylmethionine proteins, indicating that GDGT cyclization occurs through a free radical mechanism. In addition, we demonstrate that GrsA introduces rings specifically at the C-7 position of the core GDGT lipid, while GrsB cyclizes at the C-3 position, suggesting that cyclization patterns are differentially controlled by 2 separate enzymes and potentially influenced by distinct environmental factors. Finally, phylogenetic analyses of the Grs proteins reveal that marine Thaumarchaeota, and not Euryarchaeota, are the dominant source of cyclized GDGTs in open ocean settings, addressing a major source of uncertainty in GDGT-based paleotemperature proxy applications.

Identification of Clinical Infections of Leishmania Imported into Australia: Revising Speciation with Polymerase Chain Reaction-RFLP of the Kinetoplast Maxicircle.

Leishmaniasis is a vector-borne disease caused by protozoan parasites of the Leishmania genus. In Australia, leishmaniasis is an imported disease that is presenting itself at increased rates because of international travel, the influx of immigrants, and deployment of military operations to endemic regions. Although Leishmania species are morphologically indistinguishable, there is a strong correlation between some causative species of leishmaniasis and the subsequent response to the treatments available and patient outcome. Consequently, identification of the infective species is imperative as misidentification can result in the administering of an ineffective drug. The aim of this study was to develop a simple diagnostic tool with high sensitivity and specificity, which is capable of detecting the presence of the parasite and accurately differentiating the causative species in question. Using the advantageous properties of the maxi-circle kinetoplast DNA, a polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) targeting the ND7 gene was developed for the analysis of imported cases of human leishmaniasis in Australia. Designed as a dual analysis, concurrent PCR of Leishmania maxi-circle DNA and digestion with two separate enzymes (NlaIII and HpyCH4IV), this study provides an appraisal on 24 imported cases of leishmaniasis between 2008 and 2017. Five Leishmania species were reported, with members of the Viannia subgenus being the most common. The implementation of novel diagnostic procedures for leishmaniasis such as the one reported here is needed to establish a gold standard practice for the diagnosis and treatment of leishmaniasis.

Silk fibroin-derived polypeptides additives to promote hydroxyapatite nucleation in dense collagen hydrogels.

Silk fibroin-derived polypeptides (FDPs) are polypeptides resulting from the enzymatic separation of the hydrophobic crystalline (Cp) and hydrophilic electronegative amorphous (Cs) components of silk fibroin (SF). The role of these polypeptides in promoting the nucleation of hydroxyapatite (HA) has been previously investigated, yet is still not fully understood. Here we study the potential of HA mineralization via FDPs incorporated at 1:10, 1:2 and 1:1 in a plastically compressed (PC) and dense collagen (DC) scaffold. Scaffolds were immersed in simulated body fluid (SBF) at physiological conditions (pH = 7.4, 37°C) to promote biomineralization. The effect of Cs and Cp to promote HA nucleation was investigated at different time points, and compared to pure DC scaffolds. Characterization of Cs and Cp fragments using Liquid Chromatography–Mass Spectrometry (LCMS) showed little difference in the amino acid composition of the FDPs. Results obtained in vitro using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM) X-Ray Diffraction (XRD) and mass analysis showed little difference between scaffolds that incorporated Cs, Cp, and DC hydrogels. These results demonstrated that silk FDPs incorporation are not yet suitable to promote HA nucleation in vivo without further refining the collagen-FDP system.

Symmetric-Key Encryption Based on Bioaffinity Interactions

The research presented here shows a bridge between biochemistry and cryptography. Enzyme-based assays were used in a new methodology linked to ciphers and cipher systems. Three separate enzyme assays, alkaline phosphatase (ALP) (E.C. 3.1.3.1), lysozyme (E.C. 3.2.1.17), and horseradish peroxidase (HRP) (E.C. 1.11.1.7), were used to create a cipher key in order to encrypt a message. By choosing certain parameters for one's experiment that are performed in the same way as a person receiving the message, correct encryption and decryption keys would be produced, resulting in a correct encryption and decryption of a message. It is imperative that both parties perform the same experiment under the same conditions in order to correctly interpret the message. Bioaffinity-based assays, in particular enzymatic assays, provide a specific, yet flexible mechanism to use for the encryption of messages. Because of the nature of this process there are a multitude of sets of parameters that may be chosen, each of which would result in a different key being produced, heightening the security and the robustness of the method. This paper shows that by using this concept of forming encryption keys using a bioaffinity-based approach, one is able to properly encrypt and decrypt a message, which could be viable for other biochemically based techniques.

The changes of activity of separate carbohydrate metabolism enzymes in blood erythrocytes of pregnant rats under vanadium citrate

The aim of the work was to study the effect of vanadium citrate on the activity of glucose-6-phosphate dehydrogenase, lactate dehydrogenase, estradiol content and to establish correlations between the activity of the studied enzymes and the estradiol content in pregnant female rats under the effect of vanadium compound. The study was carried out on 25 female Wistar rats, divided into five groups: group I - non-pregnant, group II - pregnant consuming pure water without additives, groups III, IV, V - females which during the mating and pregnancy periods received the solution of vanadium citrate at the concentrations of 3.75, 15.63 and 62.5 μgV/kg of body weight, respectively. Glucose-6-phosphate dehydrogenase, lactate dehydrogenase and estradiol content increase in pregnant females of group II compared to group I of non-pregnant animals. In pregnant females, the effect of vanadium citrate resulted in the decrease in the activity of glucose-6-phosphate dehydrogenase and lactate dehydrogenase in the blood of animals in groups IV and V, and the content of estradiol in the animals of all three experimental groups (III, IV, V), compared to group II of pregnant females. The values of glucose-6-phosphate dehydrogenase activity in the animals of group IV, which received the solution of vanadium citrate at the concentration of 15.63 μgV/kg of body weight, was similar to that of the animals in group I. This may indicate the normalizing effect of vanadium citrate on the activity of glucose-6-phosphate dehydrogenase at the indicated concentration, which is probably due to the ability of the vanadium microelement to inhibit the activity of this enzyme. Vanadium citrate at the concentration of 15.63 μgV/kg of body weight caused the recovery of the enzyme activity to the values of the activity in group І.

Highly specific sophorose β-glucosidase from Sphingomonas elodea ATCC 31461 for the efficient conversion of stevioside to rubusoside

Enzyme specificity and particularity is needed not only in enzymatic separation methods, but also in enzymatic determination methods for plant compound extraction. Stevioside, rubusoside, and rebaudioside A are natural sweet compounds from plants. These compounds have the same skeleton and only contain different side-chain glucosyl groups, making them difficult to separate. However, enzymes that target diterpenoid compounds and show specific activity for side-chain glucosyl groups are rare. Herein, we report the identification and characterization of an enzyme that can target both diterpenoid compounds and sophorose, namely, β-glucosidase SPBGL1 from Sphingomonas elodea ATCC 31461. SPBGL1 displayed high specificity toward sophorose, and activity toward stevioside, but not rebaudioside A. The stevioside conversion rate was 98%. SPBGL1 also operated at high substrate concentrations, such as in 50% crude steviol glycoside extract. Glucose liberated from stevioside was easy to quantify using the glucose oxidase method, allowing the stevioside content to be determined.

Multivariate spectrofluorimetric detection of lipase isolated from Serratia marcescens in chromatographic fractions.

Lipases are ubiquitous enzymes and widespread in nature. They have been widely purified as one of the most important enzymes in molecular biosciences and biotechnology. In this paper, the extracellular lipase was separated from Serratia marcescens. The separated enzyme was purified partially by ammonium sulfate precipitation, dialysis and gel filtration chromatography. Presence of the lipase in chromatography fractions was assayed by the hydrolysis of paranitrophenyl palmitate (pNPP) as substrate. The excitation and emission (EEM) fluorescence spectra of purified lipase in chromatographic fractions were investigated. The study demonstrates an application of fluorescence spectroscopy, combined with multivariate regression methods, to the analysis of fluorescent lipase component. N-way partial least squares (N-PLS) was utilized to show the importance of region selection in calibration modeling of the data. Genetic algorithm (GA) optimization was applied to improve the performance of radial basis function network based regression model. RBF-ANN was used to calibrate and predict lipase activity. The analytical performance of RBF-ANN method was characterized by Q^2parameter. The value of Q^2 was 0.919. The proposed method was successfully applied to the analysis of protein containing fractions and in order to explore the three way fluorescence data array from separated fractions, parallel factor analysis (PARAFAC) was applied. The fluorescence signal was resolved into excitation and emission profiles of the pure fluorescent compounds.

Production of Whey-Derived DPP-IV Inhibitory Peptides Using an Enzymatic Membrane Reactor

Continuous processing in the production of peptides is an area of increased interest. In this study, an enzymatic membrane reactor (EMR) was developed whereby whey protein isolate was used as a substrate to prepare DPP-IV inhibitory and radical scavenging peptides via enzymatic hydrolysis. Two separate enzymes were tested: Corolase 2TS and Protamex in conventional batch processes and the EMR. Neither enzyme was considered effective at producing peptides with radical scavenging activity when measured using a DPPH assay. However, both enzymes were capable of producing DPP-IV inhibitory peptides. Corolase and Protamex both produced similar DPP-IV inhibition levels upon completion of batch experiments. In the EMR process, permeate in the Protamex run showed 33.7% lower IC50 value compared to the continuous Corolase run. Protamex was a better enzyme at producing the DPP-IV inhibitory effect. The continuous (EMR) production method showed an increased productivity over batch for both enzymes.

Escherichia coli Uses Separate Enzymes to Produce H2S and Reactive Sulfane Sulfur From L-cysteine.

Hydrogen sulfide (H2S) has been proposed to have various physiological functions, and it may function through reactive sulfane sulfur. Since the two sulfur forms often coexist, they are normally considered interchangeable. Here, we characterized the production of H2S and reactive sulfane sulfur in Escherichia coli MG1655 and found that they are not readily interchangeable. They are primarily produced from L-cysteine via different enzymes. L-Cysteine desulfhydrases consumed L-cysteine and directly generated H2S. The produced H2S was mainly lost through evaporation into the gas phase, as E. coli does not have enzymes that easily oxidize H2S to reactive sulfane sulfur. L-Cysteine desulfhydrases were also responsible for the degradation of exogenous L-cysteine, which is toxic at high levels. Conversely, L-cysteine aminotransferase and 3-mercaptopyruvate sulfurtransferase sequentially metabolized endogenous L-cysteine to produce cellular reactive sulfane sulfur; however, it was not a major route of H2S production during normal growth or during the metabolism of exogenous L-cysteine by the resting cells. Noticeably, the 3-mercaptopyruvate sulfurtransferase mutant contained less reactive sulfane sulfur and displayed a greater sensitivity to H2O2 than did the wild type. Thence, reactive sulfane sulfur is likely a common cellular component, involved in protein sulfhydration and protecting cells from oxidative stress.

豌豆蛋白O<sup>2-</sup>清除肽酶解优化及分离制备工艺研究

豌豆蛋白O<sup>2-</sup>清除肽酶解优化及分离制备工艺研究

DNA-induced liquid phase condensation of cGAS activates innate immune signaling.

The binding of DNA to cyclic GMP-AMP synthase (cGAS) leads to the production of the secondary messenger cyclic GMP-AMP (cGAMP), which activates innate immune responses. Here, we show that DNA binding to cGAS robustly induced the formation of liquid-like droplets in which cGAS was activated. The disordered and positively charged cGAS N-terminus enhanced cGAS–DNA phase separation by increasing the valencies of DNA binding. Long DNA was more efficient in promoting cGAS liquid phase separation and cGAS enzyme activity than short DNA. Moreover, free zinc ion enhanced cGAS enzyme activity both in vitro and in cells by promoting cGAS–DNA phase separation. These results demonstrated that the DNA-induced phase transition of cGAS promotes cGAMP production and innate immune signaling.

Sonicated membrane separation

Membrane separation processes are currently proven technologies in many areas. The main limitation of these processes is the accumulation of matter at the membrane surface which leads to two phenomena: concentration polarization and membrane fouling. According to the publications of numerous authors permeate flux could be increased by sonication. Our work focuses on separation of real broth by sonicated ultrafiltration. The broth was originated from hydrolysis of grounded corn-cob by xylanase enzyme. The filtration was carried out in a laboratory batch stirred cell with a sonication rod sonicator. In our work the effect of the stirring, the intensity of sonication and the membrane-transducer distance was studied on the efficiency of the ultrafiltration and on the quality of separated enzymes. Results reveal that xylanase enzyme can be effectively separated from real fermentation broth by ultrafiltration and enzymes keep their activity after the process. Enzyme activity tests show that low energy sonication is not harmful to the enzyme.

Diatom Allantoin Synthase Provides Structural Insights into Natural Fusion Protein Therapeutics.

Humans have lost the ability to convert urate into the more soluble allantoin with the evolutionary inactivation of three enzymes of the uricolytic pathway. Restoration of this function through enzyme replacement therapy can treat severe hyperuricemia and Lesch-Nyhan disease. Through a genomic exploration of natural gene fusions, we found that plants and diatoms independently evolved a fusion protein (allantoin synthase) complementing two human pseudogenes. The 1.85-Å-resolution crystal structure of allantoin synthase from the diatom Phaeodactylum tricornutum provides a rationale for the domain combinations observed in the metabolic pathway, suggesting that quaternary structure is key to the evolutionary success of protein domain fusions. Polyethylene glycol (PEG) conjugation experiments indicate that a PEG-modified form of the natural fusion protein provides advantages over separate enzymes in terms of activity maintenance and manufacturing of the bioconjugate. These results suggest that the combination of different activities in a single molecular unit can simplify the production and chemical modification of recombinant proteins for multifunctional enzyme therapy.

Aldosterone‐Induced Transcripts Identified from Rapidly Isolated Collecting Duct Cells

In the distal nephron, the steroid hormone aldosterone regulates sodium reabsorption via the epithelial sodium channel ENaC. Previous attempts to identify the aldosterone‐induced proteins that mediate the action of aldosterone on ENaC have primarily used transcriptional profiling of cultured cells. Here, we present a method to rapidly isolate collecting duct cells from the mouse kidney for transcriptional profiling. Our objective is to use this method, in combination with dietary sodium manipulation, to identify transcripts that are differentially expressed in the collecting ducts of mouse kidney under conditions of high versus low plasma aldosterone.An antibody against the cell adhesion molecule L1‐CAM was previously used for fluorescence activated cell sorting (FACS) of collecting duct cells from human kidney. We verified L1‐CAM is also expressed in the collecting ducts of mouse kidney using immunofluorescence. We next developed a protocol for physical and enzymatic separation of mouse kidney into a single cell suspension. The kidney cells were labeled with L1‐CAM magnetic microbeads as well as antibodies against markers for endothelial cells (CD31) and immune cells (CD45). This allowed isolation of an L1‐CAM+ cell population using magnetic activated cell sorting (MACS), followed by separation of collecting duct cells from L1‐CAM+ endothelial and immune cells using FACS. RNA was purified from the FACS‐isolated collecting duct cells and, following poly(A) selection, used to generate Illumina TruSeq libraries. The libraries were sequenced on the Illumina HiSeq platform and the reads were aligned to the mouse genome using the Subread aligner. The aligned reads were mapped to transcripts using feature Counts and differentially expressed transcripts are identified using EdgeR.To identify transcripts that are differentially expressed in the collecting ducts of mouse kidney under conditions of high versus low plasma aldosterone, C57BL/6J mice were fed sodium‐deficient diet (to stimulate endogenous aldosterone) or high‐sodium diet (to suppress endogenous aldosterone). After 5 days of dietary sodium manipulation, the kidneys were harvested, collecting duct cells were isolated, and RNA was sequenced and analyzed according to the above protocol. Of the differentially expressed transcripts, 234 were up‐regulated by aldosterone (more highly expressed in the sodium‐deficient diet samples) while 276 were down‐regulated by aldosterone (more highly expressed in the high‐sodium diet samples); false discovery rate < 0.05, no log2FC or log2CPM threshold. The transcriptome data were then compared with recently published single‐cell RNA‐seq data for the major collecting duct cell types, specifically intercalated cells and principal cells. It was found that 16 of the up‐regulated transcripts and 32 of the down‐regulated transcripts were highly expressed in principal cells, thereby limiting the number of candidate transcripts for subsequent validation. Of the transcripts that were highly expressed in principal cells, Sgk1 was the most differentially expressed transcript induced by aldosterone.Support or Funding InformationU.S. Department of Veterans Affairs: I01BX002228This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Process Intensification of Enzymatic Fatty Acid Butyl Ester Synthesis Using a Continuous Centrifugal Contactor Separator.

Fatty acid butyl esters were synthesized from sunflower oil with 1-butanol using a homogeneous Rhizomucor miehei lipase in a biphasic organic (triglyceride, 1-butanol, hexane)– water (with enzyme) system in a continuous setup consisting of a cascade of a stirred tank reactor and a continuous centrifugal contactor separator (CCCS), the latter being used for integrated reaction and liquid–liquid separation. A fatty acid butyl ester yield up to 93% was obtained in the cascade when operated in a once-through mode. The cascade was run for 8 h without operational issues. Enzyme recycling was studied by reintroduction of the water phase from the CCCS outlet to the stirred tank reactor. Product yield decreased over time to an average of 50% of the initial value, likely due to accumulation of 1-butanol in water phase, loss of enzyme due to agglomeration, and the formation of a separate enzyme layer.

Genetic bypass of essential RNA repair enzymes in budding yeast.

RNA repair enzymes catalyze rejoining of an RNA molecule after cleavage of phosphodiester linkages. RNA repair in budding yeast is catalyzed by two separate enzymes that process tRNA exons during their splicing and HAC1 mRNA exons during activation of the unfolded protein response (UPR). The RNA ligase Trl1 joins 2′,3′-cyclic phosphate and 5′-hydroxyl RNA fragments, creating a phosphodiester linkage with a 2′-phosphate at the junction. The 2′-phosphate is removed by the 2′-phosphotransferase Tpt1. We bypassed the essential functions of TRL1 and TPT1 in budding yeast by expressing “prespliced,” intronless versions of the 10 normally intron-containing tRNAs, indicating this repair pathway does not have additional essential functions. Consistent with previous studies, expression of intronless tRNAs failed to rescue the growth of cells with deletions in components of the SEN complex, implying an additional essential role for the splicing endonuclease. The trl1Δ and tpt1Δ mutants accumulate tRNA and HAC1 splicing intermediates indicative of RNA repair defects and are hypersensitive to drugs that inhibit translation. Failure to induce the unfolded protein response in trl1Δ cells grown with tunicamycin is lethal owing to their inability to ligate HAC1 after its cleavage by Ire1. In contrast, tpt1Δ mutants grow in the presence of tunicamycin despite reduced accumulation of spliced HAC1 mRNA. We optimized a PCR-based method to detect RNA 2′-phosphate modifications and show they are present on ligated HAC1 mRNA. These RNA repair mutants enable new studies of the role of RNA repair in cellular physiology.

Magnetic field remotely controlled selective biocatalysis

Many applications for medical therapy, biotechnology and biosensors rely on efficient delivery and release of active substances. Here, we demonstrate a platform that explores magnetic-field-responsive compartmentalization of biocatalytic reactions for well-controlled release of chemicals or biological materials on demand. This platform combines two different kinds of core–shell magnetic nanoparticle: one loaded with enzymes and another with substrate-bound therapeutic (bio)chemicals. Both cargos are shielded with a polymer brush structure of the nanoparticle shell, which prevents any enzyme–substrate interactions. The shield’s barrier is overcome when a relatively weak (a fraction of 1 T) external magnetic field is applied and the enzyme and the substrate are merged and forced to interact in the generated nanocompartment. The merged biocatalytic nanoparticles liberate the substrate-bound therapeutic drugs when the enzymes degrade the substrate. The developed platform provides a proof of concept for the remotely controlled release of drugs or (bio)chemicals using the energy of a non-invasive, weak magnetic field. Biocatalysis, if selective, offers great potential for the well-controlled release of drugs and other payloads. Here, Minko and co-workers separate enzymes and substrates by loading them onto individual, polymer-coated nanoparticles, and show that a magnetic field switches on the catalytic activity by merging the polymer shells.