Journal articles: 'Enzymes Separation'

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Lemmer, Balázs, Szabolcs Kertész, Gábor Keszthelyi-Szabó, Kerime Özel, and Cecilia Hodúr. "Sonicated membrane separation." Progress in Agricultural Engineering Sciences 14, s1 (July 2018): 89–99. http://dx.doi.org/10.1556/446.14.2018.s1.9.

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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.

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Dey, Krishna Kanti, Sambeeta Das, Matthew F. Poyton, Samudra Sengupta, Peter J. Butler, Paul S. Cremer, and Ayusman Sen. "Chemotactic Separation of Enzymes." ACS Nano 8, no. 12 (October 2014): 11941–49. http://dx.doi.org/10.1021/nn504418u.

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Prouteau, Manoël, and Robbie Loewith. "Regulation of Cellular Metabolism through Phase Separation of Enzymes." Biomolecules 8, no. 4 (December 3, 2018): 160. http://dx.doi.org/10.3390/biom8040160.

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Metabolism is the sum of the life-giving chemical processes that occur within a cell. Proper regulation of these processes is essential for all organisms to thrive and prosper. When external factors are too extreme, or if internal regulation is corrupted through genetic or epigenetic changes, metabolic homeostasis is no longer achievable and diseases such as metabolic syndrome or cancer, aging, and, ultimately, death ensue. Metabolic reactions are catalyzed by proteins, and the in vitro kinetic properties of these enzymes have been studied by biochemists for many decades. These efforts led to the appreciation that enzyme activities can be acutely regulated and that this regulation is critical to metabolic homeostasis. Regulation can be mediated through allosteric interactions with metabolites themselves or via post-translational modifications triggered by intracellular signal transduction pathways. More recently, enzyme regulation has attracted the attention of cell biologists who noticed that change in growth conditions often triggers the condensation of diffusely localized enzymes into one or more discrete foci, easily visible by light microscopy. This reorganization from a soluble to a condensed state is best described as a phase separation. As summarized in this review, stimulus-induced phase separation has now been observed for dozens of enzymes suggesting that this could represent a widespread mode of activity regulation, rather than, or in addition to, a storage form of temporarily superfluous enzymes. Building on our recent structure determination of TOROIDs (TORc1 Organized in Inhibited Domain), the condensate formed by the protein kinase Target Of Rapamycin Complex 1 (TORC1), we will highlight that the molecular organization of enzyme condensates can vary dramatically and that future work aimed at the structural characterization of enzyme condensates will be critical to understand how phase separation regulates enzyme activity and consequently metabolic homeostasis. This information may ultimately facilitate the design of strategies to target the assembly or disassembly of specific enzymes condensates as a therapeutic approach to restore metabolic homeostasis in certain diseases.

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Eoff, R. L., and K. D. Raney. "Helicase-catalysed translocation and strand separation." Biochemical Society Transactions 33, no. 6 (October 26, 2005): 1474–78. http://dx.doi.org/10.1042/bst0331474.

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Helicases are molecular-motor enzymes that manipulate DNA or RNA during replication, repair, recombination, transcription, translation and processing of nucleic acids. The mechanisms for helicase activity have been studied intensely over the past decade. Recent advances in our understanding of the helicase mode of action have led to a general convergence of models that describe this diverse class of enzymes. One mechanism has been proposed that appears to have withstood the test of time, namely the inchworm mechanism. As the name implies, this mechanism involves a process whereby a helicase maintains at least two sites of contact with the nucleic acid. These binding sites can move relative to one another in a sequential fashion, resulting in net movement of the enzyme along the nucleic acid. The inchworm mechanism appears to be applicable to oligomeric states beyond the simple monomeric molecular motor. Although there are certainly many pertinent questions that remain unanswered, striking similarities in both form and function of seemingly disparate enzymes are becoming evident.

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Keçeci, Kübra, Balázs Lemmer, Szabolcs Kertész, Gábor Keszthelyi-Szabó, Zsuzsanna László, and Cecilia Hodúr. "The effect of the implementation of ultrasound in enzyme separation." Analecta Technica Szegedinensia 9, no. 2 (June 12, 2015): 34–41. http://dx.doi.org/10.14232/analecta.2015.2.34-41.

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Enzymes are biological catalysts that generally are designed to do one job well, but to do one job only. Therefore, the enzymes that catalyze the hydrolysis of cellulose to sugar do not break down the sugars. Enzymatic hydrolysis processes have been under development for only 10 years. The important research issues include understanding the processes necessary to render the crystalline cellulose easily digestible, understanding and improving the basic mechanisms in the hydrolysis step, and developing better and less expensive enzymes. The other way to make a process less expensive may be the recycling of enzymes. The essential unit operation in the bioethanol production is the cellulose enzymatic degradation, so the question of recycling is very important. In our work the sonication assisted ultrafiltration was investigated as a potential method for enzyme recycling. The results showed the ultrasound effects the permeate flux since the resistance is reduced by the sonication. The sonicated enzyme keeps its activity so the recycling mechanism might be used for bioethanol production.

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Kazenwadel, F., H. Wagner, B. E. Rapp, and M. Franzreb. "Optimization of enzyme immobilization on magnetic microparticles using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) as a crosslinking agent." Analytical Methods 7, no. 24 (2015): 10291–98. http://dx.doi.org/10.1039/c5ay02670a.

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Zeitoune, Jessica Florinda. "Enzime recovery by ultrafiltration from broth." Analecta Technica Szegedinensia 8, no. 2 (May 12, 2014): 23–27. http://dx.doi.org/10.14232/analecta.2014.2.23-27.

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Recycling waste products of food industry is important: one side because of the environmental aspects and the other side because of the economic reasons. The one of the most preferred basic material for second generation bio-fuels might be the tobacco (Ábel et al. 2011). The cost of the process depends on the cost of the hydrolysis of cellulose/lignocelluloses i.e. and the cost of the enzymes. These enzymes are very expensive and that is why it is so important to find a good enzyme recovery method. In my research the membrane separation was used for enzyme recovery. Different polyether-sulphone membranes with cut-off value of 7 kDa (PES7) and 10 kDa (PES10) were used for separation the hydrolyzate.

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WANG, DANHUI, ZIYUAN WANG, FEI HE, AMANDA J. KINCHLA, and SAM R. NUGEN. "Enzymatic Digestion for Improved Bacteria Separation from Leafy Green Vegetables." Journal of Food Protection 79, no. 8 (August 1, 2016): 1378–86. http://dx.doi.org/10.4315/0362-028x.jfp-15-581.

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ABSTRACT An effective and rapid method for the separation of bacteria from food matrix remains a bottleneck for rapid bacteria detection for food safety. Bacteria can strongly attach to a food surface or internalize within the matrix, making their isolation extremely difficult. Traditional methods of separating bacteria from food routinely involve stomaching, blending, and shaking. However, these methods may not be efficient at removing all the bacteria from complex matrices. Here, we investigate the benefits of using enzyme digestion followed by immunomagnetic separation to isolate Salmonella from spinach and lettuce. Enzymatic digestion using pectinase and cellulase was able to break down the structure of the leafy green vegetables, resulting in the detachment and release of Salmonella from the leaves. Immunomagnetic separation of Salmonella from the liquefied sample allowed an additional separation step to achieve a more pure sample without leaf debris that may benefit additional downstream applications. We have investigated the optimal combination of pectinase and cellulase for the digestion of spinach and lettuce to improve sample detection yields. The concentrations of enzymes used to digest the leaves were confirmed to have no significant effect on the viability of the inoculated Salmonella. Results reported that the recovery of the Salmonella from the produce after enzyme digestion of the leaves was significantly higher (P <0.05) than traditional sample preparation methods to separate bacteria (stomaching and manually shaking). The results demonstrate the potential for use of enzyme digestion prior to separation can improve the efficiency of bacteria separation and increase the likelihood of detecting pathogens in the final detection assay.

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Sher, Hassan, Hazrat Ali, Muhammad H. Rashid, Fariha Iftikhar, Saif-ur-Rehman, Muhammad S. Nawaz, and Waheed S. Khan. "Enzyme Immobilization on Metal-Organic Framework (MOF): Effects on Thermostability and Function." Protein & Peptide Letters 26, no. 9 (September 16, 2019): 636–47. http://dx.doi.org/10.2174/0929866526666190430120046.

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MOFs are porous materials with adjustable porosity ensuing a tenable surface area and stability. MOFs consist of metal containing joint where organic ligands are linked with coordination bonding rendering a unique architecture favouring the diverse applications in attachment of enzymes, Chemical catalysis, Gases storage and separation, biomedicals. In the past few years immobilization of soluble enzymes on/in MOF has been the topic of interest for scientists working in diverse field. The activity of enzyme, reusability, storage, chemical and thermal stability, affinity with substrate can be greatly improved by immobilizing of enzyme on MOFs. Along with improvement in enzymes properties, the high loading of enzyme is also observed while using MOFs as immobilization support. In this review a detail study of immobilization on/in Metalorganic Frameworks (MOFs) have been described. Furthermore, strategies for the enzyme immobilization on MOFs and resulting in improved catalytic performance of immobilized enzymes have been reported.

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Ullah, Najeeb, Mujaddad Ur Rehman, Abid Sarwar, Muhammad Nadeem, Rubina Nelofer, Hafiz Abdullah Shakir, Muhammad Irfan, et al. "Purification, Characterization, and Application of Alkaline Protease Enzyme from a Locally Isolated Bacillus cereus Strain." Fermentation 8, no. 11 (November 11, 2022): 628. http://dx.doi.org/10.3390/fermentation8110628.

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Among the microbial enzymes protease and amylase are the most valuable enzymes which have been has diversified applications and used extensively because of their capabilities in the degradation of organic wastes, application in biofuels, agricultural, pharmaceuticals, chemical and biotechnological industries. The aim of the current research work was the purification, characterization and application of alkaline proteases extracted from Bacillus cereus AUST-7. Various concentrations of ammonium sulphate were applied for enzyme precipitation. Sephadex-G 100 was used in FPLC system for separation of protease from other proteins. SDS-PAGE was used to measure the molecular weight of required alkaline protease. Relative activities were determined against different pH, temperature, and incubation period to measure the enzymes activity. Stability of pH, temperature and various metal ions and inhibiter were also studied. Purified enzymes were applied on the goat skin to explore the dehairing efficacy. A 6.5 purification fold and 1163.50 U/mg of specific activity were obtained at 70% saturation and 35. 91 purification fold and 8902 U/mg of specific activity were observed after FPLC separation. The 35 kDa molecular size of protease enzyme was exhibited on the SDS-PAGE. The purified enzyme was stable at pH 10, temperature 55 °C and 35 min of incubation period. The purified enzyme was found to be stable at pH 8–11, thermo-stability at 50 °C and phenyl methyl sulphonyl fluoride (PMSF) and di-isopropyl fluorophosphates (DFP) inhibited the enzyme activity. The enzyme has good potential as dehairing agent in leather industries.

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FABER, K. "ChemInform Abstract: Chiral Separation Techniques Using Hydrolytic Enzymes." ChemInform 24, no. 13 (August 20, 2010): no. http://dx.doi.org/10.1002/chin.199313071.

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Arancibia, Ramón A., and Carl E. Motsenbocker. "ENZYME ACTIVITY IN TABASCO FRUIT SEPARATION ZONES." HortScience 31, no. 5 (September 1996): 746a—746. http://dx.doi.org/10.21273/hortsci.31.5.746a.

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Red-mature Tabasco (Capsicum frutescens) fruit (`McIlhenny Select') normally separate easily at the junction of the fruit and receptacle or calyx. Differences in fruit detachment force (FDF) between two lines, one that separates readily (`McIlhenny Select') and one that does not (`Hard Pick'), have been reported previously (Motsenbocker et al., 1995). In this study, enzyme activity from the detachment area was analyzed by viscosity reduction. The reaction mixture was 0.3% pectin in 20 mm NaAc, pH 5.5, for polygalacturonase (PG) and 0.6% carboxymethyl cellulose (CMC) in 20 mm NaPO4, pH 6.0, for cellulase. Preliminary data indicated that PG and cellulase enzyme activity increased during fruit ripening in both lines. Only cellulase activity, however, correlated with FDF. In addition, the activity of both enzymes was higher in the `McIlhenny Select' line than the `Hard Pick' line at the orange and red-mature stages.

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13

Gesek, F. A., D. W. Wolff, and J. W. Strandhoy. "Improved separation method for rat proximal and distal renal tubules." American Journal of Physiology-Renal Physiology 253, no. 2 (August 1, 1987): F358—F365. http://dx.doi.org/10.1152/ajprenal.1987.253.2.f358.

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We modified and improved enzyme digestion and density gradient separation procedures to obtain fractions of proximal and distal renal tubules with high yield and viability. Kidneys from two anesthetized adult Wistar rats were flushed with Krebs-Henseleit buffer (KHB) and then perfused in situ with recirculated KHB containing collagenase and hyaluronidase at 125 mmHg. Cortices were excised, minced, and incubated in KHB containing enzymes for 35 min at 37 degrees C. Dissociated tubules were removed at 10-min intervals, rinsed, and placed in KHB containing 10% calf serum, vitamins, and amino acids at 4 degrees C. Separation was achieved by suspending the tissue in 45% isosmotic Percoll layered over an undiluted Percoll cushion and centrifuging. Proximal tubules sedimented near the cushion. Distal segments were isolated in the uppermost bands of a second 35% Percoll separation. Viability was greater than 95% as measured by lactate dehydrogenase leakage and quantitated by oxygen consumption and ATP content. Basal oxygen consumption was greater than 33 nmol O2 X min-1 X mg protein-1 in all fractions and was stimulated by succinate and inhibited by amiloride and ouabain. Basal ATP content averaged 9.7 nmol/mg ATP. An average 3.3-fold separation for the proximal fraction and 24.5-fold separation for the distal fraction was assessed by the enrichment of six specific enzyme markers, with several of the markers indicating separations up to 32-fold. Isolated tubules also displayed functional responses to parathyroid hormone and vasopressin. Distal, but not proximal, segments demonstrated significantly increased adenosine 3',5'-cyclic monophosphate formation with vasopressin.

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Moliner, M., D. Saura, J. M. Ros, and J. Laencina. "Cross-flow Filtration through Ceramic Membranes of Enzymes and Degradation Products from Enzymatic Peeling of Satsuma Mandarin Segments." Food Science and Technology International 14, no. 5_suppl (October 2008): 71–76. http://dx.doi.org/10.1177/1082013208094681.

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The present work evaluates the possibility of using cross-flow filtration to recover enzymatic activities from commercial enzymes used for peeling mandarin segments. Two ceramic membranes of different pore size and molecular weight cut-off were assayed. The membrane of 40 kDa molecular weight cut-off provided better separation of enzymes and carbohydrates than the membrane of 0.14 μm pore size, since the enzymes were readily retained in the retentate fraction, while carbohydrates easily passed into the permeate fraction. After separation, both fractions (enzymes and carbohydrates) could be further used.

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Batrinescu, Gheorghe, Dana Garganciuc, Ovidiu Popa, and Mihaela Olteanu. "Kinetic Study of Maltodextrine Saccharification Process using Amyloglucosidase Covalently Immobilised." Revista de Chimie 59, no. 1 (February 9, 2008): 30–32. http://dx.doi.org/10.37358/rc.08.1.1700.

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The membranes with immobilized enzymes have a double role, as a separation barrier and a biocatalyst. The membranes immobilize the enzymes in insoluble state by direct binding (e.g. covalent binding) or in soluble state, by adsorption at the separation surface, depending on the polymer nature and the membrane structure. The researches purpose was to emphasize the biocatalytic activity of a membrane-immobilized enzyme system. This paper relates the original results from the kinetic study of maltodextrine saccharification process. The dextrines are obtained by enzymatic hydrolise of starch with a-amilase.The process took place into an enzymatic membrane bioreactor equipped with an active membrane from brominated polyphenileneoxide with 28% bromination degree, having amyloglucosidase covalently immobilized. In this bioreactor carries on the conversion of dextrines to maltose and glucose, under the biocatalytic action of amyloglucosidase.

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Li, Can, Zhishang Shi, Jinxing Cai, Ping Wang, Fang Wang, Meiting Ju, Jinpeng Liu, and Qilin Yu. "Synthesis of Phenylboronic Acid-Functionalized Magnetic Nanoparticles for Sensitive Soil Enzyme Assays." Molecules 27, no. 20 (October 14, 2022): 6883. http://dx.doi.org/10.3390/molecules27206883.

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Soil enzymes, such as invertase, urease, acidic phosphatase and catalase, play critical roles in soil biochemical reactions and are involved in soil fertility. However, it remains a great challenge to efficiently concentrate soil enzymes and sensitively assess enzyme activity. In this study, we synthesized phenylboronic acid-functionalized magnetic nanoparticles to rapidly capture soil enzymes for sensitive soil enzyme assays. The iron oxide magnetic nanoparticles (MNPs) were firstly prepared by the co-precipitation method and then functionalized by (3-aminopropyl)triethoxysilane, polyethyleneimine and phenylboric acid in turn, obtaining the final nanoparticles (MNPPBA). Protein-capturing assays showed that the functionalized MNPs had a much higher protein-capturing capacity than the naked MNPs (56% versus 6%). Moreover, MNPPBA almost thoroughly captured the tested enzymes, i.e., urease, invertase, and alkaline phosphatase, from enzyme solutions. Based on MNPPBA, a soil enzyme assay method was developed by integration of enzyme capture, magnetic separation and trace enzyme analysis. The method was successfully applied in determining trace enzyme activity in rhizosphere soil. This study provides a strategy to sensitively determine soil enzyme activity for mechanistic investigation of soil fertility and plant–microbiome interaction.

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Akin, D. E., W. H. Morrison, G. R. Gamble, L. L. Rigsby, Gunnar Henriksson, and Karl-Erik L. Eriksson. "Effect of Retting Enzymes on the Structure and Composition of Flax Cell Walls." Textile Research Journal 67, no. 4 (April 1997): 279–87. http://dx.doi.org/10.1177/004051759706700407.

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Commercial enzyme mixtures are tested for their possibly selective degradation of flax ( Linum usitatissimum L.) stem components in relation to the retting process in producing linen. Structural and chemical compositional results from treatments are obtained using scanning electron microscopy, histochemistry, gas-liquid chromatography, 13C cp mas nmr spectrometry, and mid-infrared spectroscopy. Flaxzyme and Ultrazym and an enriched pectinase mixture (epm), which was not developed for flax retting but is included for comparison, are tested for their activity toward cell wall components and used in various concentrations for “enzyme-retting” of flax. Ariane flax stem sections are incubated with enzymes in a rotary incubator and the fibers are manually separated from the residual core. All of the commercial enzyme mixtures have cellulase, pectinase, and hemicellulase activities, but individual enzyme activities vary. Activities against the soluble test substrates do not predict the activity against natural fibers. At about equal protein concentrations, Flaxzyme treatment appears to facilitate bast fiber removal better than the other enzymes, with Ultrazym nearly as effective and epm the least effective. The ranking of effectiveness is generally supported by the amounts of uronic acid, arabinose, and xylose removed from the stems analyzed chemically. Increased enzyme levels generally facilitate removal of matrix carbohydrates from the flax. All enzymes separate bast fibers from the lignified core and partially from the cuticle near the cut surface of the stem sections, but the enzymes do not work far from the exposed ends. Retting quality is defined more by the degree of cell wall degradation and fiber separation than by any differences in kinds of cell walls degraded by the various enzymes. The cuticle remains attached to the fiber at times, apparently reducing access of the enzymes to the matrix polysacchrides and suggesting some recalcitrance of epidermal cells (and therefore loss of cuticle) to biodegradation. Lignin remains in the middle lamellae after enzyme retting and would likely prevent separation of the fiber bundles. Some solubilzation of the inner secondary wall of the flax fiber appears to occur with Flaxzyme. The structural and chemical analyses characterize alterations in flax bast after enzyme retting and would be useful in ranking the specificity and effectiveness of cell wall degradation.

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Ashida, Hiroyuki, Kaho Murakami, Kenji Inagaki, Yoshihiro Sawa, Hisashi Hemmi, Yugo Iwasaki, and Tohru Yoshimura. "Evolution and properties of alanine racemase from Synechocystis sp. PCC6803." Journal of Biochemistry 171, no. 4 (December 30, 2021): 421–28. http://dx.doi.org/10.1093/jb/mvab155.

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Abstract Alanine racemase (EC 5.1.1.1) depends on pyridoxal 5′-phosphate and catalyses the interconversion between L- and D-Ala. The enzyme is responsible for the biosynthesis of D-Ala, which is an essential component of the peptidoglycan layer of bacterial cell walls. Phylogenetic analysis of alanine racemases demonstrated that the cyanobacterial enzyme diverged before the separation of gram-positive and gram-negative enzymes. This result is interesting considering that the peptidoglycans observed in cyanobacteria seem to combine the properties of those in both gram-negative and gram-positive bacteria. We cloned the putative alanine racemase gene (slr0823) of Synechocystis sp. PCC6803 in Escherichia coli cells, expressed and purified the enzyme protein and studied its enzymological properties. The enzymatic properties of the Synechocystis enzyme were similar to those of other gram-positive and gram-negative bacterial enzymes. Alignment of the amino acid sequences of alanine racemase enzymes revealed that the conserved tyrosine residue in the active centre of most of the gram-positive and gram-negative bacterial enzymes has been replaced with tryptophan in most of the cyanobacterial enzymes. We carried out the site-directed mutagenesis involving the corresponding residue of Synechocystis enzyme (W385) and revealed that the residue is involved in the substrate recognition by the enzyme.

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Flechsler, Jennifer, Thomas Heimerl, Harald Huber, Reinhard Rachel, and Ivan A. Berg. "Functional compartmentalization and metabolic separation in a prokaryotic cell." Proceedings of the National Academy of Sciences 118, no. 25 (June 14, 2021): e2022114118. http://dx.doi.org/10.1073/pnas.2022114118.

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The prokaryotic cell is traditionally seen as a “bag of enzymes,” yet its organization is much more complex than in this simplified view. By now, various microcompartments encapsulating metabolic enzymes or pathways are known for Bacteria. These microcompartments are usually small, encapsulating and concentrating only a few enzymes, thus protecting the cell from toxic intermediates or preventing unwanted side reactions. The hyperthermophilic, strictly anaerobic Crenarchaeon Ignicoccus hospitalis is an extraordinary organism possessing two membranes, an inner and an energized outer membrane. The outer membrane (termed here outer cytoplasmic membrane) harbors enzymes involved in proton gradient generation and ATP synthesis. These two membranes are separated by an intermembrane compartment, whose function is unknown. Major information processes like DNA replication, RNA synthesis, and protein biosynthesis are located inside the “cytoplasm” or central cytoplasmic compartment. Here, we show by immunogold labeling of ultrathin sections that enzymes involved in autotrophic CO2 assimilation are located in the intermembrane compartment that we name (now) a peripheric cytoplasmic compartment. This separation may protect DNA and RNA from reactive aldehydes arising in the I. hospitalis carbon metabolism. This compartmentalization of metabolic pathways and information processes is unprecedented in the prokaryotic world, representing a unique example of spatiofunctional compartmentalization in the second domain of life.

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Csanádi, József, Ottilia Bara-Herczegh, Attila Szabolcsi, József Mihalkó, and Ádám Lőrincz. "Effect of different commercial enzymes on the clotting of milk and certain properties of curd." Analecta Technica Szegedinensia 15, no. 1 (August 10, 2021): 73–81. http://dx.doi.org/10.14232/analecta.2021.1.73-81.

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More researches published data about the milk curd properties, evaluated the importance in the cheese making, but an analysis of importance of these properties in practical applications is usually lacking. We investigate the milk curd behaviour using different enzyme preparations at the cutting of curd. We focused on the well measurable properties as clotting time, viscosity of curd, texture properties an whey separation rate of cur at cutting time. Approximately five minutes difference was determined between the clotting times. Investigated the curd properties we found significant differences between the hardness on samples clotted with CHY MAX® M 1000 and NATUREN® Premium 145 enzymes. Other properties did not show significant differences, but in some case differences were remarkable. Discovered differences e.g. approx. 5% whey separation rate difference and the different trends of adhesive force and adhesiveness confirm that such studies should be carried out. Summarized effect of different enzymes can alter the cheese making technology in the practice, significantly. Considering every aspect, in our investigation the CHY MAX® M 1000 enzyme seemed the best.

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Harsa, Sebnem, and Shintaro Furusaki. "Chromatographic separation of amyloglucosidase from the mixtures of enzymes." Biochemical Engineering Journal 8, no. 3 (October 2001): 257–61. http://dx.doi.org/10.1016/s1369-703x(01)00123-1.

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Nguyen, Binh Thanh, and Min-Jung Kang. "Application of Capillary Electrophoresis with Laser-Induced Fluorescence to Immunoassays and Enzyme Assays." Molecules 24, no. 10 (May 22, 2019): 1977. http://dx.doi.org/10.3390/molecules24101977.

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Capillary electrophoresis using laser-induced fluorescence detection (CE-LIF) is one of the most sensitive separation tools among electrical separation methods. The use of CE-LIF in immunoassays and enzyme assays has gained a reputation in recent years for its high detection sensitivity, short analysis time, and accurate quantification. Immunoassays are bioassay platforms that rely on binding reactions between an antigen (analyte) and a specific antibody. Enzyme assays measure enzymatic activity through quantitative analysis of substrates and products by the reaction of enzymes in purified enzyme or cell systems. These two category analyses play an important role in the context of biopharmaceutical analysis, clinical therapy, drug discovery, and diagnosis analysis. This review discusses the expanding portfolio of immune and enzyme assays using CE-LIF and focuses on the advantages and disadvantages of these methods over the ten years of existing technology since 2008.

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Uheda, Eiji, Yoko Akasaka, and Hiroyuki Daimon. "Morphological aspects of the shedding of surface layers from peanut roots." Canadian Journal of Botany 75, no. 4 (April 1, 1997): 607–11. http://dx.doi.org/10.1139/b97-067.

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Epidermal cells and cells originating in the outer cortex form the surface layers of peanut (Arachis hypogaea) roots, the outermost of which separate and shed from the periphery. Shedding takes place continuously and over the whole surface of the root. Light and electron microscopic studies revealed that the shedding of surface layers involves modification of cell walls and separation of intact cells. Wall breakdown, as well as the expansion of cells resulting from wall breakdown, might facilitate the separation of intact cells. Examination of enzymes revealed that cellulase showed much higher activity in the shedding layers than in the remaining tissues. The results suggest that the cell separation process in peanut roots involves a wall-degrading enzyme-mediated mechanism. Key words: Arachis hypogaea, morphology, root, shedding, surface layers, wall breakdown.

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Thurley, Kevin, Christopher Herbst, Felix Wesener, Barbara Koller, Thomas Wallach, Bert Maier, Achim Kramer, and Pål O. Westermark. "Principles for circadian orchestration of metabolic pathways." Proceedings of the National Academy of Sciences 114, no. 7 (February 3, 2017): 1572–77. http://dx.doi.org/10.1073/pnas.1613103114.

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Circadian rhythms govern multiple aspects of animal metabolism. Transcriptome-, proteome- and metabolome-wide measurements have revealed widespread circadian rhythms in metabolism governed by a cellular genetic oscillator, the circadian core clock. However, it remains unclear if and under which conditions transcriptional rhythms cause rhythms in particular metabolites and metabolic fluxes. Here, we analyzed the circadian orchestration of metabolic pathways by direct measurement of enzyme activities, analysis of transcriptome data, and developing a theoretical method called circadian response analysis. Contrary to a common assumption, we found that pronounced rhythms in metabolic pathways are often favored by separation rather than alignment in the times of peak activity of key enzymes. This property holds true for a set of metabolic pathway motifs (e.g., linear chains and branching points) and also under the conditions of fast kinetics typical for metabolic reactions. By circadian response analysis of pathway motifs, we determined exact timing separation constraints on rhythmic enzyme activities that allow for substantial rhythms in pathway flux and metabolite concentrations. Direct measurements of circadian enzyme activities in mouse skeletal muscle confirmed that such timing separation occurs in vivo.

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Xie, Xiao Ling, Bing Li, Zhi Qing Wu, Shou Li Dong, and Lin Li. "Preparation of Cross-Linked Cellulase Aggregates onto Magnetic Chitosan Microspheres." Advanced Materials Research 550-553 (July 2012): 1566–71. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.1566.

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The cellulase was immobilized onto magnetic chitosan microspheres carrier as cross-linked enzymes aggregates (CLEAs). It was precipitated with 95% saturation ammonia sulfate and cross-linked with 3% (v/v) glutaraldehyde. Efficient enzyme activity about 50.6% was obtained when cellulase concentration was 1.0mg/mL after cross-linking for 7 h at 30○C. The CLEAs was advantageous on stabilities and magnetic responsiveness for separation.

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Xi, Yongkang, Bo Liu, Shuxin Wang, Xiaonan Huang, Hang Jiang, Shouwei Yin, To Ngai, and Xiaoquan Yang. "Growth of Au nanoparticles on phosphorylated zein protein particles for use as biomimetic catalysts for cascade reactions at the oil–water interface." Chemical Science 12, no. 11 (2021): 3885–89. http://dx.doi.org/10.1039/d0sc06649d.

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A robust chemo- and biocatalytic cascade PIC with a recovery catalyst and a separation product was developed. The results groundbreakingly highlighted the preliminary applications of artificial enzymes and bio-enzymes in a one-pot cascade PIC.

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WANG, HENRY Y., MIN ZHANG, and TADAYUKI IMANAKA. "Screening and Separation of ?-Lactam Antibiotics Using Protein-engineered Enzymes." Annals of the New York Academy of Sciences 613, no. 1 Enzyme Engine (December 1990): 376–84. http://dx.doi.org/10.1111/j.1749-6632.1990.tb18182.x.

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Bronnenmeier, K., C. Ebenbichler, and W. L. Staudenbauer. "Separation of the cellulytic and xylanolytic enzymes of Clostridium stercorarium." Journal of Chromatography A 521, no. 2 (November 1990): 301–10. http://dx.doi.org/10.1016/0021-9673(90)85054-y.

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Huang, Shih Yow, Ching Kuan Lin, and Long Yih Juang. "Separation and purification of enzymes by continuous pH-parametric pumping." Biotechnology and Bioengineering 27, no. 10 (October 1985): 1451–57. http://dx.doi.org/10.1002/bit.260271009.

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Day, Frances A., and Daniel A. Neufeld. "Use of Enzyme Overlay Membranes to Survey Proteinase Activity in Frozen Sections: Cathepsin-like and Plasmin-like Activity in Regenerating Newt Limbs." Journal of Histochemistry & Cytochemistry 45, no. 6 (June 1997): 779–83. http://dx.doi.org/10.1177/002215549704500602.

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We present a method that permits extremely simple and rapid screening of proteolytic enzyme activity in sectioned tissues. Enzyme overlay membranes (EOMs) are custom-made membranes designed to fluoresce at sites of specific proteolytic enzyme activity after separation of proteins by gel electrophoresis. EOMs, selected to detect either plasmin-like or cathepsin B-like activity, have been used in a novel way to document the distribution of enzyme activity in frozen sectioned tissues. When moistened membranes were placed in contact with sectioned regenerating newt limbs, a fluorescent pattern of enzyme activity was generated. In limbs at 3 hr post amputation, cathepsin B-like activity was prominent across the amputation site but plasmin-like activity was distributed in dermal and deeper proximal tissues, suggesting different roles for these two classes of enzymes. EOM enzymology in situ (EEI) on frozen sectioned tissues may be a widely useful technique to display distribution and level of activity of proteolytic enzymes in various systems.

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O, Kar-Min, Yaw L. Siow, and Patrick C. Choy. "Hamster liver cholinephosphotransferase and ethanolaminephosphotransferase are separate enzymes." Biochemistry and Cell Biology 67, no. 10 (October 1, 1989): 680–86. http://dx.doi.org/10.1139/o89-102.

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CDP-choline: 1,2-diacylglycerol cholinephosphotransferase (EC 2.7.8.2) and CDP-ethanolamine:1,2-diacylglycerol ethanolaminephosphotransferase (EC 2.7.8.1) are microsomal enzymes that catalyze the final steps in the syntheses of phosphatidylcholine and phosphatidylethanolamine via the CDP-choline and CDP-ethanolamine pathways, respectively. Both enzyme activities were cosolubilized from hamster liver microsomes by Triton QS-15. Limited separation of these two activities was achieved by ion-exchange chromatography. The partially purified phosphotransferases displayed a higher sensitivity than microsomal phosphotransferases towards exogenous phospholipids and showed an absolute requirement for divalent cations. Upon purification, cholinephosphotransferase was more stable to heat treatment than ethanolaminephosphotransferase. The two enzymes exhibited distinct pH optima and responded differently to exogenous phospholipids. Our results clearly indicate that cholinephosphotransferase and ethanolaminephosphotransferase are separate enzymes.Key words: cholinephosphotransferase, ethanolaminephosphotransferase, phosphatidylcholine biosynthesis, hamster liver.

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Ahmad Rizal Lim, Fatin Nasreen, Fauziah Marpani, Victoria Eliz Anak Dilol, Syazana Mohamad Pauzi, Nur Hidayati Othman, Nur Hashimah Alias, Nik Raikhan Nik Him, Jianquan Luo, and Norazah Abd Rahman. "A Review on the Design and Performance of Enzyme-Aided Catalysis of Carbon Dioxide in Membrane, Electrochemical Cell and Photocatalytic Reactors." Membranes 12, no. 1 (December 27, 2021): 28. http://dx.doi.org/10.3390/membranes12010028.

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Multi-enzyme cascade catalysis involved three types of dehydrogenase enzymes, namely, formate dehydrogenase (FDH), formaldehyde dehydrogenase (FaldDH), alcohol dehydrogenase (ADH), and an equimolar electron donor, nicotinamide adenine dinucleotide (NADH), assisting the reaction is an interesting pathway to reduce thermodynamically stable molecules of CO2 from the atmosphere. The biocatalytic sequence is interesting because it operates under mild reaction conditions (low temperature and pressure) and all the enzymes are highly selective, which allows the reaction to produce three basic chemicals (formic acid, formaldehyde, and methanol) in just one pot. There are various challenges, however, in applying the enzymatic conversion of CO2, namely, to obtain high productivity, increase reusability of the enzymes and cofactors, and to design a simple, facile, and efficient reactor setup that will sustain the multi-enzymatic cascade catalysis. This review reports on enzyme-aided reactor systems that support the reduction of CO2 to methanol. Such systems include enzyme membrane reactors, electrochemical cells, and photocatalytic reactor systems. Existing reactor setups are described, product yields and biocatalytic productivities are evaluated, and effective enzyme immobilization methods are discussed.

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Matveeva, Valentina G., and Lyudmila M. Bronstein. "Magnetic Nanoparticle-Containing Supports as Carriers of Immobilized Enzymes: Key Factors Influencing the Biocatalyst Performance." Nanomaterials 11, no. 9 (August 31, 2021): 2257. http://dx.doi.org/10.3390/nano11092257.

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In this short review (Perspective), we identify key features of the performance of biocatalysts developed by the immobilization of enzymes on the supports containing magnetic nanoparticles (NPs), analyzing the scientific literature for the last five years. A clear advantage of magnetic supports is their easy separation due to the magnetic attraction between magnetic NPs and an external magnetic field, facilitating the biocatalyst reuse. This allows for savings of materials and energy in the biocatalytic process. Commonly, magnetic NPs are isolated from enzymes either by polymers, silica, or some other protective layer. However, in those cases when iron oxide NPs are in close proximity to the enzyme, the biocatalyst may display a fascinating behavior, allowing for synergy of the performance due to the enzyme-like properties shown in iron oxides. Another important parameter which is discussed in this review is the magnetic support porosity, especially in hierarchical porous supports. In the case of comparatively large pores, which can freely accommodate enzyme molecules without jeopardizing their conformation, the enzyme surface ordering may create an optimal crowding on the support, enhancing the biocatalytic performance. Other factors such as surface-modifying agents or special enzyme reactor designs can be also influential in the performance of magnetic NP based immobilized enzymes.

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Wang, Stephanie, Connor Davis, and Lior Sepunaru. "Liquid-Liquid Phase Separation Effects on Electron Transfer Kinetics and Thermodynamics." ECS Meeting Abstracts MA2022-01, no. 43 (July 7, 2022): 1873. http://dx.doi.org/10.1149/ma2022-01431873mtgabs.

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Water-in-water droplets formed by liquid-liquid phase separations are a method of membraneless cellular compartmentalization, allowing a cell to quickly organize enzymes to respond to events without the high energy expenditure associated with forming membraned compartments. This organization drives increased catalytic rates of enzyme reactions. Though some of this surge can be attributed to localization and condensation of substrate and enzyme, it cannot account for the total increase. We hypothesize that the inner environ of a LLPS droplet provides a unique solvation environment compared to the bulk phase and should thus alter the thermodynamics of reactions within it. Using an extension of Marcus theory, we describe these effects which are observed in a shifted formal potential. Here, we demonstrate this proof of concept, employing fluorescent dyes as redox reporters: single-entity electrochemistry is used to quantify probes partitioned into LLPS droplets. These findings should aid biophysical explorations of these membraneless organelles of emerging interest and importance. Figure 1

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35

Wallin, R., S. D. Patrick, and L. F. Martin. "Vitamin K1 reduction in human liver. Location of the coumarin-drug-insensitive enzyme." Biochemical Journal 260, no. 3 (June 15, 1989): 879–84. http://dx.doi.org/10.1042/bj2600879.

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The antidotal effect of vitamin K in overcoming poisoning by coumarin anticoagulant drugs is mediated by a vitamin K-reducing enzyme of the endoplasmic reticulum [Wallin & Martin (1987) Biochem. J. 241, 389-396]. With microsomes obtained from human liver biopsies, we have investigated the localization and the transverse orientation of this enzyme in the endoplasmic reticulum and compared its orientation to that of the other enzymes of the vitamin K-dependent carboxylation system. All enzymes were protected by the microsomal membrane and thus appear to have a luminal orientation in the endoplasmic reticulum, consistent with their role in the vitamin K-dependent modification of secretory glycoproteins. Separation of rough and smooth microsomes showed that vitamin K-dependent carboxylase activity was 6-fold higher in rough than in smooth microsomes. Vitamin K1 reduction by the coumarin-drug-sensitive (pathway I) and -insensitive (pathway II) enzymes of the vitamin K-dependent carboxylation system was the same in rough and smooth microsomes. The data suggest a close association between the pathway I and II enzymes in the endoplasmic reticulum. These pathways may be partial reactions of multienzyme complex which carries out the various activities associated with the vitamin K-dependent carboxylation system.

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Furukawa, K., and S. Roth. "Co-purification of galactosyltransferases from chick-embryo liver." Biochemical Journal 227, no. 2 (April 15, 1985): 573–82. http://dx.doi.org/10.1042/bj2270573.

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Two galactosyltransferases with nearly identical Mr values were purified 5000-7000-fold from microsomal membranes of chick-embryo livers by using several affinity columns. One enzyme transfers galactose from UDP-galactose to form a β-(1→4)-linkage to GlcNAc (N-acetylglucosamine) or AsAgAGP [asialo-agalacto-(alpha 1-acid glycoprotein)]. The other enzyme forms a β-(1→3)-linkage to AsOSM [asialo-(ovine submaxillary mucin)]. Both enzymes were solubilized (85%) from a microsomal pellet by using 1% Triton X-100 in 0.1 M-NaCl. The supernatant activities were subjected to DEAE-Sepharose chromatography and four affinity columns: UDP-hexanolamine-Sepharose, alpha-lactalbumin-Sepharose, GlcNAc-Sepharose and either AsAgAGP-Sepharose or AsOSM-Sepharose. The AsAgAGP enzyme [(1→4)-transferase] and the AsOSM enzyme [(1→3)-transferase] behave identically on the DEAE-Sepharose and UDP-hexanolamine-Sepharose columns, and similarly on the alpha-lactalbumin-Sepharose column. Final separation of the two enzymes, however, could only be achieved on affinity columns of their immobilized respective acceptors. Both purified enzymes migrate as a single band on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis after silver staining, and both have an apparent Mr of 68 000. The enzymes were radioiodinated and again subjected to sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Radioautographic analyses showed only one, intensely radioactive, band. Activity stains performed for both transferases after cellulose acetate electrophoresis indicate that, with this system too, both activities have identical mobilities, and co-migrate, as well, with the major, silver-stained, protein band. Kinetic studies with the purified enzymes show that the Km value for GlcNAc, for the (1→4)-transferase, is 4mM; for the (1→3)-transferase the Km value for AsOSM is 5mM, in terms of GalNAc (N-acetylgalactosamine) equivalents. Both enzymes have a Km value of 25 microM for UDP-galactose.

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37

Polgár, L., F. Erdélyi, E. Hajnal, M. Löw, L. Gráf, and B. D. Korant. "Separation of native and truncated forms of poliovirus protease 3C produced in Escherichia coli." Biochemical Journal 290, no. 3 (March 15, 1993): 797–800. http://dx.doi.org/10.1042/bj2900797.

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Poliovirus protease 3C is a cysteine enzyme that is essential for the processing of the viral precursor polyprotein containing structural proteins and enzymes, including the protease itself. We have constructed the plasmid pSD/PV3C which produced protease 3C as inclusion bodies when expressed in Escherichia coli. In addition to the full-length protease, a truncated form was also generated, starting from an internal initiation site (Met-27). The enzyme was renatured by dilution of a 6 M guanidinium chloride solution of the inclusion bodies, and the proteins were precipitated from the diluted solution with ammonium sulphate. By extracting the precipitate with a buffer solution, the full-length enzyme could be completely separated from its N-terminally truncated form. Size-exclusion chromatography of the extracted protease 3C resulted in an active enzyme which appeared homogeneous by SDS/PAGE. For measuring the activity of the protease, a spectrofluorimetric method was devised to monitor the hydrolysis continuously, which is simpler and more precise than the h.p.l.c. technique used previously.

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38

Adelson, J. W., and P. E. Miller. "Heterogeneity of the exocrine pancreas." American Journal of Physiology-Gastrointestinal and Liver Physiology 256, no. 5 (May 1, 1989): G817—G825. http://dx.doi.org/10.1152/ajpgi.1989.256.5.g817.

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The exocrine pancreas is generally considered to be a homogeneous organ at the morphological and functional levels. Recent work, reviewed here, has provided multiple reasons to question this. Morphologically, differences have been found in cell size and digestive enzyme content in "peri-" vs. "teleinsular" acini by methods including acinar separation, enzyme assay, and both light and electron microscopic immunocytochemistry. Detection of several blood group antigens in human acinar tissue showed striking cellular heterogeneity in a mosaic pattern. Stimulation of pancreatic lobules by specific secretagogues and separation of individual zymogen granules with microfluorometric assay of enzyme content also confirmed heterogeneity at the lobular and organellar level. Functionally, evidence that nonparallel digestive enzyme secretion can be taken as direct support for acinar heterogeneity is reviewed, as is the work leading to direct demonstration of secretagogue-specific heterogeneous sequestration and storage of nascent digestive enzyme protein. A general overview of pancreatic acinar cell specificity is presented; the model incorporates temporal changes in secretion from eligible acini, with secretagogue specificity of whole acini containing specific preset mixtures of digestive enzymes.

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Raspi, G., A. Lo Moro, M. Spinetti, and G. Tesi. "Hydrophobic interaction chromatography separation and determination of glycolytic enzymes-method validation." Chromatographia 46, no. 9-10 (November 1997): 471–76. http://dx.doi.org/10.1007/bf02496363.

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40

Sharma, Aparna, Kalyani Mondal, and Munishwar Nath Gupta. "Separation of enzymes by sequential macroaffinity ligand-facilitated three-phase partitioning." Journal of Chromatography A 995, no. 1-2 (May 2003): 127–34. http://dx.doi.org/10.1016/s0021-9673(03)00522-3.

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Teotia, Sunita, and M. N. Gupta. "Reversibly soluble macroaffinity ligand in aqueous two-phase separation of enzymes." Journal of Chromatography A 923, no. 1-2 (July 2001): 275–80. http://dx.doi.org/10.1016/s0021-9673(01)00968-2.

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42

Shih, Frederick F., and Kim Daigle. "Use of Enzymes for the Separation of Protein from Rice Flour." Cereal Chemistry Journal 74, no. 4 (July 1997): 437–41. http://dx.doi.org/10.1094/cchem.1997.74.4.437.

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43

Ehsani, Neda, Marianne Nyström, Heikki Ojamo, and Matti Siika-aho. "Separation of enzymes produced by Trichoderma reesei with hydrophobic ultrafiltration membranes." Process Biochemistry 31, no. 3 (January 1996): 253–63. http://dx.doi.org/10.1016/0032-9592(95)00057-7.

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44

Wiafe-Kwagyan, M., G. T. Odamtten, and M. Obodai. "Differentiation of Two Pleurotus Species Based on the Restrictive Digestion Profile of the Internal Transcribed Spacer Region." Ghana Journal of Science 61, no. 2 (January 31, 2021): 105–12. http://dx.doi.org/10.4314/gjs.v61i2.10.

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Two oyster mushrooms (Pleurotus eous P-31 and P. ostreatus EM-1) are under either cottage industry or semi-commercial cultivation in Ghana. The latter (P. ostreatus) is already well known to the public and on the shelf of some leading supermarkets. There is morphological resemblance between the two species making it difficult for the untrained eye to distinguish between them except for the colour difference. In this study, molecular methods were employed to differentiate among the two species. The Internal Transcribed Spacer ITS 1 and ITS 4 regions of the rDNA of the two oyster species were amplified by the conventional PCR using the universal primer pair, ITS 1 and ITS 4 followed by restrictive digestion with enzymes, (Hh I, Hinf I, Rsa I and Hae III). The two species could not be separated based on the amplified bands only, as both produced a characteristic band size of 650 bp. Gel profiling showing restrictive patterns generated by the four enzymes indicated that only the Hae III restrictive enzyme was effective in separating P. eous P-31 and P. ostreatus EM-1. This is the first record of the separation of the Ghanaian Pleurotus species by molecular methods indicating their genetic differences.

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45

Ninh, Pham Huynh, Kohsuke Honda, Yukako Yokohigashi, Kenji Okano, Takeshi Omasa, and Hisao Ohtake. "Development of a Continuous Bioconversion System Using a Thermophilic Whole-Cell Biocatalyst." Applied and Environmental Microbiology 79, no. 6 (January 18, 2013): 1996–2001. http://dx.doi.org/10.1128/aem.03752-12.

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ABSTRACTThe heat treatment of recombinant mesophilic cells having heterologous thermophilic enzymes results in the denaturation of indigenous mesophilic enzymes and the elimination of undesired side reactions; therefore, highly selective whole-cell catalysts comparable to purified enzymes can be readily prepared. However, the thermolysis of host cells leads to the heat-induced leakage of thermophilic enzymes, which are produced as soluble proteins, limiting the exploitation of their excellent stability in repeated and continuous reactions. In this study,Escherichia colicells having the thermophilic fumarase fromThermus thermophilus(TtFTA) were treated with glutaraldehyde to prevent the heat-induced leakage of the enzyme, and the resulting cells were used as a whole-cell catalyst in repeated and continuous reactions. Interestingly, although electron microscopic observations revealed that the cellular structure of glutaraldehyde-treatedE. coliwas not apparently changed by the heat treatment, the membrane permeability of the heated cells to relatively small molecules (up to at least 3 kDa) was significantly improved. By applying the glutaraldehyde-treatedE. colihavingTtFTA to a continuous reactor equipped with a cell-separation membrane filter, the enzymatic hydration of fumarate to malate could be operated for more than 600 min with a molar conversion yield of 60% or higher.

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46

Schmidt, Martin, Andrea Prager, Nadja Schönherr, Roger Gläser, and Agnes Schulze. "Reagent-Free Immobilization of Industrial Lipases to Develop Lipolytic Membranes with Self-Cleaning Surfaces." Membranes 12, no. 6 (June 9, 2022): 599. http://dx.doi.org/10.3390/membranes12060599.

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Biocatalytic membrane reactors combine the highly efficient biotransformation capability of enzymes with the selective filtration performance of membrane filters. Common strategies to immobilize enzymes on polymeric membranes are based on chemical coupling reactions. Still, they are associated with drawbacks such as long reaction times, high costs, and the use of potentially toxic or hazardous reagents. In this study, a reagent-free immobilization method based on electron beam irradiation was investigated, which allows much faster, cleaner, and cheaper fabrication of enzyme membrane reactors. Two industrial lipase enzymes were coupled onto a polyvinylidene fluoride (PVDF) flat sheet membrane to create self-cleaning surfaces. The response surface methodology (RSM) in the design-of-experiments approach was applied to investigate the effects of three numerical factors on enzyme activity, yielding a maximum activity of 823 ± 118 U m−2 (enzyme concentration: 8.4 g L−1, impregnation time: 5 min, irradiation dose: 80 kGy). The lipolytic membranes were used in fouling tests with olive oil (1 g L−1 in 2 mM sodium dodecyl sulfate), resulting in 100% regeneration of filtration performance after 3 h of self-cleaning in an aqueous buffer (pH 8, 37 °C). Reusability with three consecutive cycles demonstrates regeneration of 95%. Comprehensive membrane characterization was performed by determining enzyme kinetic parameters, permeance monitoring, X-ray photoelectron spectroscopy, FTIR spectroscopy, scanning electron microscopy, and zeta potential, as well as water contact angle measurements.

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Souza, Ranyere L., Sónia P. M. Ventura, Cleide M. F. Soares, João A. P. Coutinho, and Álvaro S. Lima. "Lipase purification using ionic liquids as adjuvants in aqueous two-phase systems." Green Chemistry 17, no. 5 (2015): 3026–34. http://dx.doi.org/10.1039/c5gc00262a.

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48

Matsui, Kenji, Yasushi Shibata, Tadahiko Kajiwara, and Akikazu Hatanaka. "Notes: Separation of 13-and 9-Hydroperoxide Lyase Activities in Cotyledons of Cucumber Seedlings." Zeitschrift für Naturforschung C 44, no. 9-10 (October 1, 1989): 883–85. http://dx.doi.org/10.1515/znc-1989-9-1031.

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Abstract In cucumber cotyledons, both C6- and C9- aldehyde were formed via hydroperoxide (HPO) lyase activity. Because it has not been elucidated whether these activities are attributed to one enzyme which can cleave both 13-and 9-HPO or to two or more enzymes each of which specifically cleaves 13-or 9-HPO , an attempt to separate HPO lyase activity was done. Ion exchange chromatography separated this activity into two fractions, one of which specifically cleaved 13-hydroperoxylinoleic acid and the other specifically cleaved the 9-isomer. 13-HPO-specific activity was most active at pH 8.0 and 9-HPO-specific one was at pH 6.5. SH -reagents inhibited both the lyases but to different extents.

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Das, Subhas, and Dileep Kumar Singh. "Purification and characterization of phosphotriesterases from Pseudomonas aeruginosa F10B and Clavibacter michiganense subsp. insidiosum SBL11." Canadian Journal of Microbiology 52, no. 2 (February 1, 2006): 157–68. http://dx.doi.org/10.1139/w05-113.

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A microbial biodegradation of monocrotophos was studied in the present investigation. The monocrotophos-degrading enzyme was purified and characterized from two soil bacterial strains. The cells were disrupted and the membrane-bound fractions were studied for purification and characterization. Solubilization of the membrane-bound fractions released nearly 80% of the bound protein. Phase separation further enriched the enzyme fraction 34–41 times. The enzyme phosphotriesterase (PTE) from both the strains was purified to more than 1000-fold with 13%–16% yield. Purified PTE from Clavibacter michiganense subsp. insidiosum SBL11 is a monomeric enzyme with a molecular mass of 43.5 kDa (pI of 7.5), while PTE from Pseudomonas aeruginosa F10B is a heterodimeric enzyme with a molecular mass of 43 and 41 kDa (pI of 7.9 and 7.35). Both purified enzymes are stable enzymes with peak activity at pH 9.0. The enzyme from strain F10B was more thermostable (half-life = 7.3 h) than that from SBL11 (half-life = 6.4 h at 50 °C), while both showed the same temperature optimum of 37 °C. Inhibitors like dithiothreitol and EDTA inhibited the purified enzyme, while p-chloromercuribenzoic acid and indoleacetic acid had a very little effect.Key words: biodegradation, monocrotophos, phosphotriesterase, Pseudomonas aeruginosa F10B, Clavibacter michiganense subsp. insidiosum SBL11.

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Nagahashi, Gerald, and Thomas S. Seibles. "Preservation and separation of endomembrane marker enzyme activity in potato leaf homogenates." Canadian Journal of Botany 64, no. 11 (November 1, 1986): 2732–37. http://dx.doi.org/10.1139/b86-362.

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To minimize rapid browning and membrane degradation of crude microsomes, leaves of Solanum tuberosum (cv. Kennebec and cv. Katahdin) were initially homogenized in the presence of various inhibitors of polyphenol oxidase, phospholipase, and protease activity. To obtain and maintain marker enzyme activities used to identify plasma membranes, Golgi membranes, and endoplasmic reticulum, it was necessary to homogenize young leaves in the presence of sulfhydryls at pH 7.8. Further separation of these membranes, as determined by distribution of total activities of marker enzymes in linear sucrose density gradients, indicated a relatively pure plasma membrane fraction (1.15 g/cm3) free from contamination by thylakoids (1.19 g/cm3) and other endomembrane components. However, the distribution of specific activities across the gradient revealed that plasma membranes isolated from green tissue may be contaminated by Golgi membranes and not necessarily by plastid membranes.

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Journal articles on the topic 'Enzymes Separation'

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