The demand for food and beverage markets has increased as a result of population increase and in view of health awareness. The quality of products from food processing industry has to be improved economically by incorporating greener methodologies that enhances the safety and shelf life via the enzymes application while maintaining the essential nutritional qualities. The utilization of enzymes is rendered more favorable in industrial practices via the modification of their characteristics as attested by studies on enzyme immobilization pertaining to different stages of food and beverage processing; these studies have enhanced the catalytic activity, stability of enzymes and lowered the overall cost. However, the harsh conditions of industrial processes continue to increase the propensity of enzyme destabilization thus shortening their industrial lifespan namely enzyme leaching, recoverability, uncontrollable orientation and the lack of a general procedure. Innovative studies have strived to provide new tools and materials for the development of systems offering new possibilities for industrial applications of enzymes. Herein, an effort has been made to present up-to-date developments on enzyme immobilization and current challenges in the food and beverage industries in terms of enhancing the enzyme stability.

• Klíčová slova
• Immobilized enzymes, enzyme reusability, enzyme stability, food industry, pharmaceuticals,
• MeSH
• enzymy imobilizované * metabolismus   MeSH
• potravinářský průmysl * MeSH
• stabilita enzymů MeSH
• technologie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• enzymy imobilizované * MeSH

Detection tubes are small devices for the colorimetric enzymatic detection of cholinesterase inhibitors such as sarin, soman, VX nerve agents and substances denoted as Novichok. These detectors contain carriers in the form of pellets with immobilized cholinesterase, substrate and detection reagent. Their advantages are portability, sensitivity and simplicity, enabling fast detection of such compounds from air and water in case of a terrorist attack or war. In general, maintaining the stability of an enzyme for a longer time is very problematic; therefore, its further enhancement is required for safety and financial reasons. In this study, the stability of our patented carriers in the form of pellets with immobilized butyrylcholinesterase containing an increasing amount of the unique sorbent Neusilin® US2 was evaluated. The samples containing Neusilin maintained the stability of the immobilized enzyme for a longer time even at higher temperature and humidity than the currently commercially used carrier without Neusilin, allowing improved detection of nerve agents.

• Klíčová slova
• Cholinesterase, Detection, Enzyme, Nerve agent, Neusilin, Stability,
• MeSH
• biosenzitivní techniky metody   MeSH
• butyrylcholinesterasa chemie   metabolismus   MeSH
• cholinesterasové inhibitory analýza   MeSH
• enzymy imobilizované chemie   metabolismus   MeSH
• kolorimetrie metody   MeSH
• nosiče léků chemie   MeSH
• silikáty metabolismus   MeSH
• sloučeniny hliníku metabolismus   MeSH
• sloučeniny hořčíku metabolismus   MeSH
• stabilita enzymů účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aluminum magnesium silicate MeSH Prohlížeč
• butyrylcholinesterasa MeSH
• cholinesterasové inhibitory MeSH
• enzymy imobilizované MeSH
• nosiče léků MeSH
• silikáty MeSH
• sloučeniny hliníku MeSH
• sloučeniny hořčíku MeSH

Different types of enzymes such as lipases, several phosphatases, dehydrogenases, oxidases, amylases and others are well suited for the reactions in SC-CO(2). The stability and the activity of enzymes exposed to carbon dioxide under high pressure depend on enzyme species, water content in the solution and on the pressure and temperature of the reaction system. The three-dimensional structure of enzymes may be significantly altered under extreme conditions, causing their denaturation and consequent loss of activity. If the conditions are less adverse, the protein structure may be largely retained. Minor structural changes may induce an alternative active protein state with altered enzyme activity, specificity and stability.

• Klíčová slova
• enzyme, hydrolysis, inactivation, supercritical carbon dioxide, synthesis,
• MeSH
• aktivace enzymů účinky léků   MeSH
• enzymy chemie   metabolismus   MeSH
• hydrolýza MeSH
• oxid uhličitý chemie   metabolismus   farmakologie   MeSH
• stabilita enzymů MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• enzymy MeSH
• oxid uhličitý MeSH

Recent investigation of somatic variations of allosterically regulated proteins in cancer genomes suggested that variations in glucokinase (GCK) might play a role in tumorigenesis. We hypothesized that somatic cancer-associated GCK variations include in part those with activating and/or stabilizing effects. We analyzed the enzyme kinetics and thermostability of recombinant proteins possessing the likely activating variations and the variations present in the connecting loop I and provided the first experimental evidence of the effects of somatic cancer-associated GCK variations. Activating and/or stabilizing variations were common among the analyzed cancer-associated variations, which was in strong contrast to their low frequency among germinal variations. The activating and stabilizing variations displayed focal distribution with respect to the tertiary structure, and were present in the surroundings of the heterotropic allosteric activator site, including but not limited to the connecting loop I and in the active site region subject to extensive rearrangements upon glucose binding. Activating somatic cancer-associated variations induced a reduction of GCK's cooperativity and an increase in the affinity to glucose (a decline in the S0.5 values). The hotspot-associated variations, which decreased cooperativity, also increased the half-maximal inhibitory concentrations of the competitive GCK inhibitor, N-acetylglucosamine. Concluded, we have provided the first convincing biochemical evidence establishing GCK as a previously unrecognized enzyme that contributes to the reprogramming of energy metabolism in cancer cells. Activating GCK variations substantially increase affinity of GCK to glucose, disrupt the otherwise characteristic sigmoidal response to glucose and/or prolong the enzyme half-life. This, combined, facilitates glucose phosphorylation, thus supporting glycolysis and associated pathways.

• Klíčová slova
• Connecting region I, Hexokinase D, Lung cancer, Melanoma, Persistent hypoglycemic hyperinsulinemia of infancy, Somatic nonsynonymous substitutions,
• MeSH
• glukokinasa chemie   genetika   MeSH
• kinetika MeSH
• lidé MeSH
• nádory enzymologie   MeSH
• rekombinantní proteiny chemie   MeSH
• stabilita enzymů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• glukokinasa MeSH
• rekombinantní proteiny MeSH

• MeSH
• biokatalýza MeSH
• dimethylsulfoxid chemie   MeSH
• enzymy chemie   metabolismus   MeSH
• kinetika MeSH
• molekulární evoluce MeSH
• proteinové inženýrství MeSH
• rozpouštědla chemie   MeSH
• simulace molekulární dynamiky MeSH
• stabilita enzymů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dimethylsulfoxid MeSH
• enzymy MeSH
• rozpouštědla MeSH

The thermal and solvent tolerance of enzymes is highly important for their industrial use. We show here that the enzyme lipase from Rhizopus oryzae exhibits exceptionally high thermal stability and high solvent tolerance and even increased activity in acetone when immobilized onto a graphene oxide (GO) nanosupport prepared by Staudenmaier and Brodie methods. We studied various forms of immobilization of the enzyme: by physical adsorption, covalent attachment, and additional crosslinking. The activity recovery was shown to be dependent on the support type, enzyme loading and immobilization procedure. Covalently immobilized lipase showed significantly better resistance to heat inactivation (the activity recovery was 65% at 70 °C) in comparison with the soluble counterpart (the activity recovery was 65% at 40 °C). Physically adsorbed lipase achieved over 100% of the initial activity in a series of organic solvents. These findings, showing enhanced thermal stability and solvent tolerance of graphene oxide immobilized enzyme, will have a profound impact on practical industrial scale uses of enzymes for the conversion of lipids into fuels.

• MeSH
• adsorpce MeSH
• aktivace enzymů MeSH
• enzymy imobilizované chemie   MeSH
• grafit chemie   MeSH
• lipasa chemie   MeSH
• nanočástice chemie   ultrastruktura   MeSH
• oxidy chemie   MeSH
• rozpouštědla chemie   MeSH
• stabilita enzymů MeSH
• teplota MeSH
• testování materiálů MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• enzymy imobilizované MeSH
• grafit MeSH
• lipasa MeSH
• oxidy MeSH
• rozpouštědla MeSH

Human NAD(P)H:quinone oxidoreductase 1 (NQO1) is a multi-functional protein whose alteration is associated with cancer, Parkinson's and Alzheimer´s diseases. NQO1 displays a remarkable functional chemistry, capable of binding different functional ligands that modulate its activity, stability and interaction with proteins and nucleic acids. Our understanding of this functional chemistry is limited by the difficulty of obtaining structural and dynamic information on many of these states. Herein, we have used hydrogen/deuterium exchange monitored by mass spectrometry (HDXMS) to investigate the structural dynamics of NQO1 in three ligation states: without ligands (NQO1apo), with FAD (NQO1holo) and with FAD and the inhibitor dicoumarol (NQO1dic). We show that NQO1apo has a minimally stable folded core holding the protein dimer, with FAD and dicoumarol binding sites populating binding non-competent conformations. Binding of FAD significantly decreases protein dynamics and stabilizes the FAD and dicoumarol binding sites as well as the monomer:monomer interface. Dicoumarol binding further stabilizes all three functional sites, a result not previously anticipated by available crystallographic models. Our work provides an experimental perspective into the communication of stability effects through the NQO1 dimer, which is valuable for understanding at the molecular level the effects of disease-associated variants, post-translational modifications and ligand binding cooperativity in NQO1.

• Klíčová slova
• NQO1, allostery, ligand binding, protein degradation, protein stability, protein structural dynamics,
• MeSH
• Alzheimerova nemoc enzymologie   MeSH
• hmotnostní spektrometrie MeSH
• konformace proteinů * MeSH
• lidé MeSH
• multimerizace proteinu genetika   MeSH
• NAD(P)H dehydrogenasa (chinon) chemie   genetika   ultrastruktura   MeSH
• nádory enzymologie   MeSH
• Parkinsonova nemoc enzymologie   MeSH
• stabilita enzymů genetika   MeSH
• vazba proteinů genetika   MeSH
• vazebná místa MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• NAD(P)H dehydrogenasa (chinon) MeSH
• NQO1 protein, human MeSH Prohlížeč

The application of enzymes is a crucial issue for current biotechnological application in pharmaceutical, as well as food and cosmetic industry. Effective platforms for enzyme immobilization are necessary for their industrial use in various biosynthesis procedures. Such platforms must provide high yield of immobilization and retain high activity at various conditions for their large-scale applications. Graphene derivatives such as hydrogenated graphene (graphane) and fluorographene can be applied for enzyme immobilization with close to 100 % yield that can result to activities of the composites significantly exceeding activity of free enzymes. The hydrophobic properties of graphene stoichiometric derivatives allowed for excellent non-covalent bonding of enzymes and their use in various organic solvents. The immobilized enzymes retain their high activities even at elevated temperatures. These findings show excellent application potential of enzyme biocatalysts immobilized on graphene stoichiometric derivatives.

• Klíčová slova
• biocatalysis, enzyme, graphene,
• MeSH
• aktivace enzymů MeSH
• biokatalýza MeSH
• enzymy imobilizované chemie   MeSH
• fluorescenční barviva chemie   MeSH
• grafit chemie   MeSH
• hydrofobní a hydrofilní interakce MeSH
• koncentrace vodíkových iontů MeSH
• lipasa chemická syntéza   MeSH
• nanostruktury chemie   MeSH
• oxidace-redukce MeSH
• povrchové vlastnosti MeSH
• rozpouštědla chemie   MeSH
• stabilita enzymů MeSH
• vysoká teplota MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• enzymy imobilizované MeSH
• fluorescenční barviva MeSH
• grafit MeSH
• lipasa MeSH
• rozpouštědla MeSH

The recent state of the knowledge of properties and structure of alpha-amylases is reviewed with the aim of elucidation the basis for their stabilization. Three principal ways for obtaining stable alpha-amylases (isolation of enzymes from extremophiles, production of extremophilic enzymes in mesophiles, and modification of mesophilic enzymes) are discussed separately. Detailed experimental examples are given for modification approaches.

• MeSH
• alfa-amylasy metabolismus   MeSH
• stabilita enzymů MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• alfa-amylasy MeSH

Enzymes play an essential role in many aspects of pharmaceutical research as drug targets, drug metabolizers, enzyme drugs and more. In this specific field, enzyme assays are required to meet a number of specific requirements, such as low cost, easy automation, and high reliability. The integration of an immobilized-enzyme reactor to capillary electrophoresis represents a unique approach to fulfilling these criteria by combining the benefits of enzyme immobilization, that is, increased stability and repeated use, as well as the minute sample consumption, short analysis time, and efficient analysis provided by capillary electrophoresis. In this review, we summarize, analyze, and discuss published works where pharmaceutically relevant enzymes were used to prepare capillary electrophoresis-integrated immobilized-enzyme reactors in an online manner. The presented assays are divided into three distinct groups based on the drug-enzyme relationship. The first, more extensively studied group employs enzymes that are considered to be therapeutic targets, the second group of assays present tools to assess drug metabolism and the third group assesses enzyme drugs. Furthermore, we examine various methods of enzyme immobilization and their implications for assay properties.

• Klíčová slova
• capillary electrophoresis, drug metabolism, druggable enzymes, immobilized-enzyme reactors,
• MeSH
• design vybavení MeSH
• elektroforéza kapilární * MeSH
• enzymatické testy MeSH
• enzymy imobilizované chemie   MeSH
• farmaceutický výzkum MeSH
• genom lidský MeSH
• kinetika MeSH
• léčivé přípravky MeSH
• lidé MeSH
• magnetismus MeSH
• proteomika MeSH
• reprodukovatelnost výsledků MeSH
• statická elektřina MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• enzymy imobilizované MeSH
• léčivé přípravky MeSH