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  • stability
  • More commonly the benefit realized from enzyme immobilization relates to the process advantages that an immobilized catalyst offers, for example, enabling continuous production, improved stability and the absence of the biocatalyst in the product stream. (rsc.org)
  • Stability: Immobilized enzymes typically have greater thermal and operational stability than the soluble form of the enzyme. (wikipedia.org)
  • However, even when an enzyme is identified as being useful for a given reaction, its application is often hampered by its lack of long-term stability under process conditions, and also by difficulties in recovery and recycling. (docme.ru)
  • A promising combination of easy separation and high stability has been reported for a lipase immobilized on magnetic g-Fe2O3 nanoparticles. (docme.ru)
  • The resulting biocatalyst exhibited significantly higher stability (over a period of almost one month) than the native enzyme in the hydrolysis of p-nitrophenyl butyrate (Figure 1). (docme.ru)
  • An appreciation of the molecular interactions between enzyme and surface support has allowed the surface chemistry and method of enzyme attachement to be fine-tuned such that activity and stability can be greatly enhanced. (rsc.org)
  • However, a method of immobilizing enzymes which is accompanied by a high degree of safety, high enzyme activity, high stability and the potential for wide-ranging applications still needs to be developed. (freepatentsonline.com)
  • To increase stability and conversion efficiency with easy separations, the first two enzymes were immobilized onto methacrylate resin. (osti.gov)
  • Covalently immobilized ADH exhibited long-term stability and efficient conversion of aldehyde to alcohol over multiple batch cycles without fusions. (osti.gov)
  • The most appealing benefits offered by IMERs include very low sample consumption (usually 10-50 μL of sample at micromolar concentration is injected when chromatographic systems are used while few microliters are required for capillary electrophoresis (CE)-based systems), increased stability of the immobilized enzyme, efficient catalysis, and short analyses (usually within minutes). (springer.com)
  • Notwithstanding all these desirable characteristic features of enzymes their widespread industrial application is often hampered by their lack of long term operational stability and shelf-storage life, and their cumbersome recovery and re-use. (wikipedia.org)
  • Improved enzyme performance via enhanced stability, over a broad pH and temperature range as well as tolerance towards organic solvents, coupled with repeated re-use is reflected in higher catalyst productivities (kg product/kg enzyme) which, in turn, determine the enzyme costs per kg product. (wikipedia.org)
  • Immobilized enzymes demonstrate very high stability and re-usability and can be used to conduct reactions in continuous mode in microreactors. (wikipedia.org)
  • substrate
  • Enzymes are adsorbed on an adsorbent powder in an aqueous medium and a water-miscible monomer is added thereto, and said monomer is polymerized to form a porous gel lump through which a substrate solution can freely pass. (google.com)
  • However, these polymers remarkably swell with water and therefore the inclusion mass is in the state of a gel lump that has no pores or voids, and therefore it is necessary to dry up the lump and pulverize it in order to convert it to a form in which the enzyme can contact with a substrate substance. (google.com)
  • The present invention relates to a method of immobilizing an enzyme using a cross-linking agent selected from iridoids to facilitate immobilization of the enzyme on a substrate. (freepatentsonline.com)
  • In order to produce such an immobilized enzyme, the invention utilizes an iridoid which facilitates the polymerization of an enzyme through intermolecular cross-linking and/or helps to form the cross-linkage between the enzyme and the support or substrate. (freepatentsonline.com)
  • SCS is the only enzyme in the citric acid cycle that catalyzes a reaction in which a nucleoside triphosphate (GTP or ATP) is formed by substrate-level phosphorylation. (wikipedia.org)
  • Regioselectivity and diastereoselectivity: Due to their complex three-dimensional structure, enzymes may distinguish between functional groups which are chemically situated in different regions of the substrate molecule. (wikipedia.org)
  • As a consequence, any type of chirality present in the substrate molecule is "recognized" upon the formation of the enzyme-substrate complex. (wikipedia.org)
  • Lys236 helps to orient the substrate while Thr11 serves to block the oxyanion hole that would convert the enzyme into an esterase. (wikipedia.org)
  • hydrolysis
  • The development and attributes of several established and emerging industrial applications for immobilized enzymes, including high- fructose corn syrup production, pectin hydrolysis , debittering of fruit juices, interesterification of food fats and oils, biodiesel production, and carbon dioxide capture are reviewed herein, highlighting factors that define the advantages of enzyme immobilization. (rsc.org)
  • catalyst
  • It is well known that enzymes are used as the catalyst that effectively promotes many chemical reactions which cannot be carried out with ordinary chemical catalysts and are indispensable materials in the fields of food industry, pharmaceutical industry and other industries. (google.com)
  • IMER
  • In this respect, it must be kept in mind that there is no universal support for all enzymes and the best suitable material depends on the enzyme characteristics and IMER application. (springer.com)
  • 1974
  • 16, 609, 1974) and a method which comprises cross-linking polyvinyl alcohol in its aqueous solution containing an enzyme (H. Maeda et al. (google.com)
  • lipase
  • Immobilization of lipase enzymes onto the methacrylate-modified paper was then accomplished, possibly due to hydrophobic interaction. (rsc.org)
  • The as-prepared immobilized lipase on methacrylate-modified paper possessed paper-specific practical utility. (rsc.org)
  • During a batch process for the nonaqueous transesterification between 1-phenylethanol and vinyl acetate to produce 1-phenylethylacetate, the paper-immobilized lipase showed high catalytic activity, selectivity and reusability, suggesting that the methacryloxy groups introduced into the cellulose paper played a key role in the hyperactivation of lipases. (rsc.org)
  • For example, lipase from Pseudomonas fluorescens was immobilized on four different carriers. (docme.ru)
  • reaction
  • Lefever R. "Dissipative Structure in Reaction-Diffusion Systems" pp.17-39 in "Analysis and Control of Immobilized Enzyme Systems" Ed. D. Thomas and J.P. Kernevez, North Holland, (1976). (springer.com)
  • The thus formed enzyme composition has long-lasting activity and thus the enzymes can be easily separated from the reaction system and can be used repeatedly. (google.com)
  • In most cases, it is very difficult from both technical and economic viewpoints to recover enzymes from the reaction mixture for repeated use thereof. (google.com)
  • But in this method, the enzyme adsorbed thereon is easily desorbed as it is repeatedly used for reaction. (google.com)
  • It also lets enzymes be held in place throughout the reaction, following which they are easily separated from the products and may be used again - a far more efficient process and so is widely used in industry for enzyme catalysed reactions. (wikipedia.org)
  • Economy: The immobilized enzyme is easily removed from the reaction making it easy to recycle the biocatalyst. (wikipedia.org)
  • As adsorption is not a chemical reaction, the active site of the immobilized enzyme may be blocked by the matrix or bead, greatly reducing the activity of the enzyme. (wikipedia.org)
  • The reaction ensures that the binding site does not cover the enzyme's active site, the activity of the enzyme is only affected by immobility. (wikipedia.org)
  • Moreover, the immobilized enzyme can be easily separated from the reaction mixture by application of a magnetic field, which either holds the immobilized enzyme in place or removes it, as the nanoparticles show very high magnetization values. (docme.ru)
  • Multiple enzymes may be introduced into the reaction, thus eliminating the need for immobilization of multiple enzymes. (wikipedia.org)
  • Succinyl coenzyme A synthetase (SCS, also known as succinyl-CoA synthetase or succinate thiokinase or succinate-CoA ligase) is an enzyme that catalyzes the reversible reaction of succinyl-CoA to succinate. (wikipedia.org)
  • The use of biocatalysis to obtain enantiopure compounds can be divided into two different methods: Kinetic resolution of a racemic mixture Biocatalysed asymmetric synthesis In kinetic resolution of a racemic mixture, the presence of a chiral object (the enzyme) converts one of the stereoisomers of the reactant into its product at a greater reaction rate than for the other reactant stereoisomer. (wikipedia.org)
  • This enzyme catalyses the following chemical reaction (1) an aliphatic (S)-hydroxynitrile ⇌ {\displaystyle \rightleftharpoons } cyanide + an aliphatic aldehyde or ketone (2) an aromatic (S)-hydroxynitrile ⇌ {\displaystyle \rightleftharpoons } cyanide + an aromatic aldehyde In nature, the liberation of cyanide serves as a defense mechanism against herbivores and microbial attack in plants. (wikipedia.org)
  • glucose
  • Conversion of glucose to fructose by xylose isomerase was first patented in the 1960s, however, the process was not industrially viable as the enzymes were suspended in solution, and recycling the enzyme was problematic. (wikipedia.org)
  • cytochrome
  • Enzymes that are important in detoxification metabolism include cytochrome P450 oxidases, UDP-glucuronosyltransferases, and glutathione S-transferases. (wikipedia.org)
  • Entrapment
  • The most frequently used immobilization techniques fall into four categories: * noncovalent adsorption or deposition, * covalent attachment, * entrapment in a polymeric gel, membrane, or capsule, * cross-linking of an enzyme. (docme.ru)
  • Basically, three traditional methods of enzyme immobilization can be distinguished: binding to a support(carrier), entrapment (encapsulation) and cross-linking. (wikipedia.org)
  • utilizes
  • The enzyme then utilizes a histidine residue to remove the phosphate group from succinyl phosphate and generate succinate. (wikipedia.org)
  • enantioselectivity
  • Cross-linked enzyme crystals (CLECs) were reported to give an increase in enantioselectivity relative to the native enzyme, but this was mostly attributed to the removal of a lessselective isoenzyme during CLEC preparation. (docme.ru)
  • In the production of fine chemicals, flavors and fragrances, agrochemicals and pharmaceuticals an important benefit of enzymes is the high degree of chemoselectivity, regioselectivity and enantioselectivity which they exhibit. (wikipedia.org)
  • protein
  • There are various ways by which one can immobilize an enzyme: Affinity-tag binding: Enzymes may be immobilized to a surface, e.g. in a porous material, using non-covalent or covalent Protein tags. (wikipedia.org)
  • Alkaline phosphatase (ALP, ALKP, ALPase, Alk Phos) (EC 3.1.3.1) or basic phosphatase is a homodimeric protein enzyme of 86 kilodaltons. (wikipedia.org)
  • Recent advances in biotechnology, particularly in genetic and protein engineering, and genetics have provided the basis for the efficient development of enzymes with improved properties for established applications and novel, tailor-made enzymes for completely new applications where enzymes were not previously used. (wikipedia.org)
  • In addition to more convenient handling of the enzyme, it provides for its facile separation from the product, thereby minimizing or eliminating protein contamination of the product. (wikipedia.org)
  • thereof
  • However, the activity of enzymes is very sensitive to change in the molecular structure thereof, and in most cases enzymes are remarkably deactivated by such chemical fixation. (google.com)
  • Porous glass and derivatives thereof are used, where the porous surface can be adapted in terms of hydrophobicity to suit the enzyme in question. (wikipedia.org)
  • thus
  • Thus, the paper-immobilized enzyme is expected to offer a green catalytic material for the effective production of useful chemicals. (rsc.org)
  • inorganic
  • In effect, along with the concomitant compound the phosphate was bound to, this enzyme yields pure inorganic phosphate which can be ultimately targeted by the phosphate-specific transport system (Pst system) for translocation into the cytosol. (wikipedia.org)
  • mechanism
  • Two recent trends are based on 1) the use of new reagents and/or carriers and 2) approaches that take into account the increasing knowledge of enzyme structure and mechanism. (docme.ru)
  • The increasing knowledge of enzyme structures and mechanism should also enable more controlled immobilizations. (docme.ru)
  • Mutagenesis experiments have determined that two glutamate residues (one near the catalytic histidine, Glu208α and one near the ATP grasp domain, Glu197β) play a role in the phosphorylation and dephosphorylation of the histidine, but the exact mechanism by which the enzyme changes conformation is not fully understood. (wikipedia.org)
  • conformation
  • This leads researchers to believe that the enzyme must undergo a major change in conformation to bring the histidine to the grasp domain and facilitate the formation of the nucleoside triphosphate. (wikipedia.org)
  • In the isomerization of xylose, crystal data has shown that xylose sugar binds to the enzyme in an open chain conformation. (wikipedia.org)
  • relates
  • More specifically, the present invention relates to a method for producing an immobilized enzyme which is equally as active as the free enzyme, is stable and nontoxic, and is hence particularly suitable for the production of food material. (freepatentsonline.com)
  • carrier
  • Throughout, a careful review of materials and techniques for the generation of functional immobilized enzymes benefits both developers and users of carrier-bound enzymes. (ellibs.com)
  • Subject matter wherein the enzyme or microbial cell is bonded to the polymeric carrier through an intermediate compound which attaches to both the enzyme and the carrier. (patentgenius.com)
  • However, physical bonding is generally too weak to keep the enzyme fixed to the carrier under industrial conditions of high reactant and product concentrations and high ionic strength. (wikipedia.org)
  • Moreover
  • Moreover, the absence of a tandem enzyme (i.e., luciferase used for kinases inhibition assay) obviates the possibility for the tested compounds to interact with the secondary enzyme. (springer.com)
  • methods
  • The enzymatic (free/immobilized) methods are more specific and rapid than the Folin method. (rsc.org)
  • We also will use scanning electron microscopy and transition electron microscopy methods to investigate the distribution of the immobilized lipases within the supporting matrix. (unl.edu)
  • Such methods may be implemented when the enzymes required are difficult or expensive to extract, an example being intracellular enzymes. (wikipedia.org)
  • Preparation
  • This technique is the only one generally applicable, and can be performed without prior enzyme purification with a pure preparation as the result. (wikipedia.org)
  • application
  • Since they can be reused continuously, immobilized enzymes have found wide application in the industrial, medical and research fields. (curehunter.com)
  • The application of immobilized enzymes in medicine is the main objective of this book. (adlibris.com)
  • This understanding has been facilitated by the application of various surface-sensitive spectroscopic techniques that allow the structure and orientation of enzymes at the solid/liquid interface to be probed, often with monolayer sensitivity. (rsc.org)
  • The main driver for the widespread application of enzymes is their small environmental footprint. (wikipedia.org)
  • alkaline
  • 3. The pH dependence of the enzymes is shifted in the alkaline direction by 0.26-1.19 units. (springer.com)
  • Alkaline phosphatase is a zinc-containing dimeric enzyme with the MW: 86,000 Da, each subunit containing 429 amino acids with four cysteine residues linking the two subunits. (wikipedia.org)
  • Alkaline phosphatase contains four Zn ions and two Mg ions, with Zn occupying active sites A and B, and Mg occupying site C, so the fully active native alkaline phosphatase is referred to as (ZnAZnBMgC)2 enzyme. (wikipedia.org)
  • Its optimum growth pH is about 7.5 for the L. lactis, however strains such as the L.brevis xylose enzyme prefer a more alkaline environment. (wikipedia.org)
  • Furthermore
  • Furthermore, the enzymes act under mild conditions, which minimizes problems of undesired side-reactions such as decomposition, isomerization, racemization and rearrangement, which often plague traditional methodology. (wikipedia.org)
  • monomer
  • For instance, a method which comprises polymerizing a water-soluble monomer suh as acrylamide in a solution containing an enzyme (K. Kawashima et al. (google.com)
  • system
  • To overcome these challenges, an alternate simplified biofuel production scheme was tested based on a cell-free immobilized enzyme system. (osti.gov)
  • However Mellor was also interested in applied science and invented and a patented system to power immobilized oxido-reductase enzymes and artificial co-factors using electrical power out of a domestic socket. (wikipedia.org)