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https://www.readbyqxmd.com/read/28330285/screening-production-optimization-and-characterization-of-%C3%AE-glucosidase-using-microbes-from-shellfish-waste
#1
Samhita Mahapatra, A S Vickram, T B Sridharan, R Parameswari, M Ramesh Pathy
An extracellular β-glucosidase was isolated from Proteus mirabilis VIT117 found to be growing on prawn shells. The enzyme production was found to be enhanced (14.58 U/ml) when the culture was maintained at pH 9 and provided with sorbitol as carbon source, yeast extract as nitrogen source and incubated at 37 °C for approximately 72 h. Statistical methods like Plackett-Burman and RSM were also applied here to study the effects of different combinations of growth parameters for the bacteria, where the most significant parameters were found to be inoculum size, pH, yeast extract, incubation time and sorbitol...
December 2016: 3 Biotech
https://www.readbyqxmd.com/read/28330261/purification-and-characterization-of-laccase-from-marasmius-species-bbkav79-and-effective-decolorization-of-selected-textile-dyes
#2
A B Vantamuri, B B Kaliwal
A novel laccase-producing white-rot fungus, Marasmius sp. BBKAV79 (Genbank Accession Number-KP455496, KP455497), was isolated and subjected to purification, characterization and dye decolorization study. The purified enzyme was obtained with a specific activity of 0.226 U mg(-1) protein and a final yield of 13.5 %. The enzyme was found to be a monomeric protein with a molecular mass of ~75 kDa as estimated by non-denaturing polyacrylamide gel electrophoresis (PAGE) and further confirmed with zymogram analysis...
December 2016: 3 Biotech
https://www.readbyqxmd.com/read/28330241/purification-characterization-gene-cloning-and-expression-of-gh-10-xylanase-penicillium-citrinum-isolate-hzn13
#3
Zabin K Bagewadi, Sikandar I Mulla, Harichandra Z Ninnekar
An extracellular thermostable xylanase (Xyl-IIb) produced by Penicillium citrinum isolate HZN13 was purified to homogeneity using DEAE-Sepharose, Sephadex G-100 and Bio-Gel P-60 chromatography with specific activity of 6272.7 U/mg and 19.6-fold purification. The purification revealed the occurrence of multiple forms of xylanases (Xyl-I, Xyl-IIa, Xyl-IIb and Xyl-III). The molecular mass of highly purified Xyl-IIb was ~31 kDa with SDS-PAGE. The enzyme was cellulase-free, thermostable (55-75 °C) and acidophilic (3...
December 2016: 3 Biotech
https://www.readbyqxmd.com/read/28330240/a-novel-cyclodextrin-glucanotransferase-from-an-alkaliphile-microbacterium-terrae-knr-9-purification-and-properties
#4
Kiransinh N Rajput, Kamlesh C Patel, Ujjval B Trivedi
Cyclodextrin glucanotransferase (CGTase, EC. 2.1.1.19) produced using new alkaliphile Microbacterium terrae KNR 9 has been purified to homogeneity in a single step by the starch adsorption method. The specific activity of the purified CGTase was 45 U/mg compared to crude 0.9 U/mg. This resulted in a 50-fold purification of the enzyme with 33 % yield. The molecular weight of the purified enzyme was found to be 27.72 kDa as determined by SDS-PAGE. Non-denaturing gel electrophoresis and activity staining confirmed the presence of CGTase in crude and the ammonium sulfate precipitate fraction...
December 2016: 3 Biotech
https://www.readbyqxmd.com/read/28330196/cloning-and-expression-of-saccharomyces-cerevisiae-suc2-gene-in-yeast-platform-and-characterization-of-recombinant-enzyme-biochemical-properties
#5
Nooshin Mohandesi, Seyed Omid Ranaei Siadat, Kamahldin Haghbeen, Ardeshir Hesampour
Invertase (EC.3.2.1.26) catalyzes the hydrolysis of sucrose to an equimolar mixture of D-glucose and D-fructose which is of interest for various industrial applications. In this research, Saccharomyces cerevisiae invertase gene (SUC2) was optimized based on Pichia pastoris codon preference. The synthetic gene was introduced into the methylotrophic yeast Pichia pastoris under the control of the inducible AOX1 promoter. High level of the extracellular recombinant invertase (R-inv) production was achieved via methanol induction for 4 days and purified by His-Tag affinity chromatography which appeared to be a mixture of glycosylated proteins with various sizes of 85-95 kDa on SDS-PAGE...
December 2016: 3 Biotech
https://www.readbyqxmd.com/read/28330171/purification-and-characterization-of-endo-%C3%AE-1-4-d-glucanase-from-trichoderma-harzianum-strain-hzn11-and-its-application-in-production-of-bioethanol-from-sweet-sorghum-bagasse
#6
Zabin K Bagewadi, Sikandar I Mulla, Harichandra Z Ninnekar
An acidophilic-solvent-thermostable endo β-1,4-D-glucanase produced from a potential Trichoderma harzianum strain HZN11 was purified to homogeneity by DEAE-Sepharose and Sephadex G-100 chromatography with 33.12 fold purification with specific activity of 66.25 U/mg and molecular mass of ~55 kDa. The optimum temperature and pH were 60 °C and 5.5 retaining 76 and 85 % of activity after 3 h, respectively. It showed stability between pH 4.5-6.0 and temperature between 50-70 °C indicating thermostability...
June 2016: 3 Biotech
https://www.readbyqxmd.com/read/28330134/phytases-from-enterobacter-and-serratia-species-with-desirable-characteristics-for-food-and-feed-applications
#7
Harpreet Kaur Kalsi, Rajveer Singh, Harcharan Singh Dhaliwal, Vinod Kumar
Phytases are enzymes of great industrial importance with wide range of applications in animal and human nutrition. These catalyze the hydrolysis of phosphomonoester bonds in phytate, thereby releasing lower forms of myo-inositol phosphates and inorganic phosphate. Addition of phytase to plant-based foods can improve its nutritional value and increase mineral bioavailability by decreasing nutritional effect of phytate. In the present investigation, 43 phytase positive bacteria on PSM plates were isolated from different sources and characterized for phytase activity...
June 2016: 3 Biotech
https://www.readbyqxmd.com/read/28330104/purification-and-characterization-of-the-enzymes-involved-in-nicotinamide-adenine-dinucleotide-degradation-by-penicillium-brevicompactum-nrc-829
#8
Thanaa Hamed Ali, Dina Helmy El-Ghonemy
The present study was conducted to investigate a new pathway for the degradation of nicotinamide adenine dinucleotide (NAD) by Penicillium brevicompactum NRC 829 extracts. Enzymes involved in the hydrolysis of NAD, i.e. alkaline phosphatase, aminohydrolase and glycohydrolase were determined. Alkaline phosphatase was found to catalyse the sequential hydrolysis of two phosphate moieties of NAD molecule to nicotinamide riboside plus adenosine. Adenosine was then deaminated by aminohydrolase to inosine and ammonia...
June 2016: 3 Biotech
https://www.readbyqxmd.com/read/28327772/the-fate-and-transformation-of-tetrabromobisphenol-a-in-natural-waters-mediated-by-oxidoreductase-enzymes
#9
Yiping Feng, Kun Lu, Shixiang Gao, Liang Mao
In this study, we examined the fate and transformation of tetrabromobisphenol A (TBBPA), mediated by the representative oxidoreductases (laccase and horseradish peroxidase (HRP)) in natural waters. Both enzymes could readily degrade TBBPA at environmentally relevant concentrations (e.g., 10 nmol L(-1)) in natural waters. After 2 hour treatment, 0.5-25% and 35-65% of TBBPA were degraded in municipal wastewater and natural surface waters by a laccase or HRP-catalyzed reaction, respectively. Enzyme kinetics evaluations indicated that the kCAT/KM ratio of HRP (1...
March 22, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28326765/a-change-in-the-rate-determining-step-of-polymerization-by-the-k289m-dna-polymerase-beta-cancer-associated-variant
#10
Khadijeh S Alnajjar, Beatriz Garcia-Barboza, Amirsoheil Negahbani, Maryam Nakhjiri, Boris A Kashemirov, Charles E McKenna, Myron F Goodman, Joann B Sweasy
K289M is a variant of DNA polymerase β (pol β) that was previously identified in colorectal cancer. The expression of this variant leads to a 16-fold increase in mutation frequency at a specific site <i>in vivo</i> and a reduction in fidelity <i>in vitro</i> in a sequence context-specific manner. Previous work shows that this reduction in fidelity results from decreased discrimination against incorrect nucleotide incorporation at the level of polymerization. To probe the transition state of the K289M mutator variant of pol β, single turnover kinetics experiments were performed using β,γ-CXY dGTP analogues with a wide range of leaving group monoacid dissociation constants (p<i>K</i><sub>a4</sub>), including a corresponding set of novel β,γ-CXY dCTP analogues...
March 22, 2017: Biochemistry
https://www.readbyqxmd.com/read/28325312/structural-and-enzyme-kinetic-studies-of-retrograded-starch-inhibition-of-%C3%AE-amylase-and-consequences-for-intestinal-digestion-of-starch
#11
Hamung Patel, Paul G Royall, Simon Gaisford, Gareth R Williams, Cathrina H Edwards, Frederick J Warren, Bernadine M Flanagan, Peter R Ellis, Peter J Butterworth
Retrograded starch is known to be resistant to digestion. We used enzyme kinetic experiments to examine how retrogradation of starch affects amylolysis catalysed by porcine pancreatic amylase. Parallel studies employing differential scanning calorimetry, infra red spectroscopy, X-ray diffraction and NMR spectroscopy were performed to monitor changes in supramolecular structure of gelatinised starch as it becomes retrograded. The total digestible starch and the catalytic efficiency of amylase were both decreased with increasing evidence of retrogradation...
May 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28323015/simultaneously-achieve-soluble-expression-and-biomimetic-immobilization-of-candida-antarctica-lipase-b-by-introducing-polyamine-tags
#12
Xiaoxue Zhou, Yu Han, Zheng Lv, Xuemei Tian, Han Li, Panpan Xie, Liangyu Zheng
Polyamine tags fused in Candida antarctica lipase B (CalB) can help achieve high soluble expression of CalB in E. coli and can directly mediate silicification, which leads to rapid formation of a CalB-silica particle complex through a one-step approach. After optimization experiments, the fused lipase CalB tagged with 6-histidine at the N terminal and 10-lysine at the C terminal (6His-CalB-10Lys) is effectively expressed with high solubility (0.1mg/mL) and specific activity (10.1U/mg), and easily cross-linked in silica particles with a high immobilization efficiency of 96...
March 16, 2017: Journal of Biotechnology
https://www.readbyqxmd.com/read/28322963/the-effect-of-oxaloacetic-acid-on-tyrosinase-activity-and-structure-integration-of-inhibition-kinetics-with-docking-simulation
#13
Lin Gou, Jinhyuk Lee, Hao Hao, Yong-Doo Park, Yi Zhan, Zhi-Rong Lü
Oxaloacetic acid (OA) is naturally found in organisms and well known as an intermediate of citric acid cycle producing ATP. We evaluated the effects of OA on tyrosinase activity and structure via integrating methods of enzyme kinetics and computational simulations. OA was found to be a reversible inhibitor of tyrosinase and its induced mechanism was the parabolic non-competitive inhibition type (IC50=17.5±0.5mM and Ki=6.03±1.36mM). Kinetic measurements by real-time interval assay showed that OA induced multi-phasic inactivation process composing with fast (k1) and slow (k2) phases...
March 16, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28322781/characterization-of-akr1b16-a-novel-mouse-aldo-keto-reductase
#14
Joan Giménez-Dejoz, Susanne Weber, Oleg A Barski, Gabriele Möller, Jerzy Adamski, Xavier Parés, Sergio Porté, Jaume Farrés
Aldo-keto reductases (AKRs) are distributed in three families and multiple subfamilies in mammals. The mouse Akr1b3 gene is clearly orthologous to human AKR1B1, both coding for aldose reductase, and their gene products show similar tissue distribution, regulation by osmotic stress and kinetic properties. In contrast, no unambiguous orthologs of human AKR1B10 and AKR1B15.1 have been identified in rodents. Although two more AKRs, AKR1B7 and AKR1B8, have been identified and characterized in mouse, none of them seems to exhibit properties similar to the human AKRs...
March 17, 2017: Chemico-biological Interactions
https://www.readbyqxmd.com/read/28322561/accuracy-of-substrate-selection-by-enzymes-is-controlled-by-kinetic-discrimination
#15
Kinshuk Banerjee, Anatoly B Kolomeisky, Oleg A Igoshin
Enzymes have the remarkable ability to select the correct substrate from the pool of chemically similar molecules. The accuracy of such a selection is determined by differences in the free energy profiles for the right and wrong reaction pathways. Here, we investigate what features of the free energy landscape govern the variation and minimization of selectivity error. It is generally believed that minimal error is affected by both kinetic (activation barrier heights) and thermodynamic (binding stability) factors...
March 21, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28322550/multiplex-substrate-profiling-by-mass-spectrometry-for-kinases-reveals-quantitative-substrate-motifs
#16
Nicole Olson Meyer, Anthony J O'Donoghue, Ursula Schulze-Gahmen, Matthew Ravalin, Steven M Moss, Michael B Winter, Giselle M Knudsen, Charles S Craik
The more than 500 protein kinases comprising the human kinome catalyze hundreds of thousands of phosphorylation events to regulate a diversity of cellular functions; however, the extended substrate specificity is still unknown for many of these kinases. We report here a method for quantitatively describing kinase substrate specificity using an unbiased peptide library-based approach with direct measurement of phosphorylation by tandem LC-MS/MS peptide sequencing (Multiplex Substrate Profiling by Mass Spectrometry, MSP-MS)...
March 21, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28322473/synthesis-of-hydrophobic-nanoparticles-for-real-time-lysozyme-detection-using-surface-plasmon-resonance-sensor
#17
Yeşeren Saylan, Fatma Yılmaz, Ali Derazshamshir, Erkut Yılmaz, Adil Denizli
Diagnostic biomarkers such as proteins and enzymes are generally hard to detect because of the low abundance in biological fluids. To solve this problem, the advantages of surface plasmon resonance (SPR) and nanomaterial technologies have been combined. The SPR sensors are easy to prepare, no requirement of labelling and can be detected in real time. In addition, they have high specificity and sensitivity with low cost. The nanomaterials have also crucial functions such as efficiency improvement, selectivity, and sensitivity of the detection systems...
March 21, 2017: Journal of Molecular Recognition: JMR
https://www.readbyqxmd.com/read/28322433/a-9-pool-metabolic-structured-kinetic-model-describing-days-to-seconds-dynamics-of-growth-and-product-formation-by-penicillium-chrysogenum
#18
Wenjun Tang, Amit T Deshmukh, Cees Haringa, Guan Wang, Walter van Gulik, Wouter van Winden, Matthias Reuss, Joseph J Heijnen, Jianye Xia, Ju Chu, Henk J Noorman
A powerful approach for the optimization of industrial bioprocesses is to perform detailed simulations integrating large scale computational fluid dynamics (CFD) and cellular reaction dynamics (CRD). However, complex metabolic kinetic models containing a large number of equations pose formidable challenges in CFD-CRD coupling and computation time afterward. This necessitates to formulate a relatively simple but yet representative model structure. Such a kinetic model should be able to reproduce metabolic responses for short-term (mixing time scale of tens of seconds) and long-term (fed-batch cultivation of hours/days) dynamics in industrial bioprocesses...
March 21, 2017: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/28320255/identification-of-highly-potent-%C3%AE-glucosidase-inhibitory-and-antioxidant-constituents-from-zizyphus-rugosa-bark-enzyme-kinetic-and-molecular-docking-studies-with-active-metabolites
#19
Jirapast Sichaem, Thammarat Aree, Kiattisak Lugsanangarm, Santi Tip-Pyang
CONTEXT: Previous studies have shown that extracts of Zizyphus rugosa Lam. (Rhamnaceae) bark contained phytoconstituents with antidiabetic potential to lower blood glucose levels in diabetic rats. However, there has been no report on the active compounds in this plant as potential antidiabetic inhibitors. OBJECTIVE: We evaluated the α-glucosidase inhibitory and antioxidant activities of Z. rugosa extract. Moreover, the active phytochemical constituents were isolated and characterized...
December 2017: Pharmaceutical Biology
https://www.readbyqxmd.com/read/28318895/competitive-protein-tyrosine-phosphatase-1b-ptp1b-inhibitors-prenylated-caged-xanthones-from-garcinia-hanburyi-and-their-inhibitory-mechanism
#20
Xue Fei Tan, Zia Uddin, Chanin Park, Yeong Hun Song, Minky Son, Keun Woo Lee, Ki Hun Park
Protein tyrosine phosphatase 1B (PTP1B) plays important role in diabetes, obesity and cancer. The methanol extract of the gum resin of Garcinia hanburyi (G. hanburyi) showed potent PTP1B inhibition at 10µg/ml. The active compounds were identified as prenylated caged xanthones (1-9) which inhibited PTP1B in dose-dependent manner. Carboxybutenyl group within caged motif (A ring) was found to play a critical role in enzyme inhibition such as 1-6 (IC50s=0.47-4.69µM), whereas compounds having hydroxymethylbutenyl 7 (IC50=70...
March 6, 2017: Bioorganic & Medicinal Chemistry
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