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https://www.readbyqxmd.com/read/29161574/fast-spectroscopic-monitoring-of-inhibitors-in-the-2g-ethanol-process
#1
Ariane S S Pinto, Marcelo P A Ribeiro, Cristiane S Farinas
One of the main challenges of second generation (2G) ethanol production is the high quantities of phenolic compounds and furan derivatives generated in the pretreatment of the lignocellulosic biomass, which inhibit the enzymatic hydrolysis and fermentation steps. Fast monitoring of these inhibitory compounds could provide better control of the pretreatment, hydrolysis, and fermentation processes by enabling the implementation of strategic process control actions. We investigated the feasibility of monitoring these inhibitory compounds by ultraviolet-visible (UV-Vis) spectroscopy associated with partial least squares (PLS) regression...
November 14, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/29161042/conformational-dynamics-of-matrix-metalloproteinase-1%C3%A2-triple-helical-peptide-complexes
#2
Tatyana G Karabencheva-Christova, Christo Z Christov, Gregg B Fields
Matrix metalloproteinase-1 (MMP-1) is a zinc-dependent protease that catalyzes hydrolysis of interstitial collagens. A previously reported X-ray crystallographic structure revealed specific interactions between a triple-helical peptide (THP) model of interstitial collagen and the hemopexin-like (HPX) and catalytic (CAT) domains of MMP-1. An NMR-based structure of MMP-1 in complex with a different THP was also solved, where docking was used to model the MMP-1•THP interactions and develop a mechanism for the early stages of collagenolysis...
November 21, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/29160871/molecular-mechanism-of-activation-of-burkholderia-cepacia-lipase-at-aqueous-organic-interfaces
#3
Ivan Pires de Oliveira, Gabriel Ernesto Jara, Leandro Martínez
Lipases are water-soluble enzymes that catalyze the hydrolysis of lipids. Since lipids are mostly hydrophobic, lipase activity occurs preferentially at interfaces of aqueous and organic phases. In this work, we study the molecular mechanisms by which the Burkholderia cepacia lipase (BCL) is activated at interfaces of water with octane and with methyl caprylate (CAME). We show that BCL assumes very rapidly a preferential orientation at the interfaces, in which the active site is exposed to the organic phase...
November 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29160840/cloning-and-molecular-characterization-of-an-alpha-glucosidase-malh-from-the-halophilic-archaeon-haloquadratum-walsbyi
#4
Mara F Cuebas-Irizarry, Ricardo A Irizarry-Caro, Carol López-Morales, Keyla M Badillo-Rivera, Carlos M Rodríguez-Minguela, Rafael Montalvo-Rodríguez
We report the heterologous expression and molecular characterization of the first extremely halophilic alpha-glucosidase (EC 3.2.1.20) from the archaeon Haloquadratum walsbyi. A 2349 bp region (Hqrw_2071) from the Hqr. walsbyi C23 annotated genome was PCR-amplified and the resulting amplicon ligated into plasmid pET28b(+), expressed in E. coli Rosetta cells, and the resulting protein purified by Ni-NTA affinity chromatography. The recombinant protein showed an estimated molecular mass of 87 kDa, consistent with the expected value of the annotated protein, and an optimal activity for the hydrolysis of α-PNPG was detected at 40 °C, and at pH 6...
November 21, 2017: Life
https://www.readbyqxmd.com/read/29159997/sporulation-capability-and-amylosome-conservation-among-diverse-human-colonic-and-rumen-isolates-of-the-keystone-starch-degrader-ruminococcus-bromii
#5
Indrani Mukhopadhya, Sarah Morais, Jenny Laverde-Gomez, Paul O Sheridan, Alan W Walker, William Kelly, Athol V Klieve, Diane Ouwerkerk, Sylvia H Duncan, Petra Louis, Nicole Koropatkin, Darrell Cockburn, Ryan Kibler, Philip J Cooper, Carlos Sandoval, Emmanuelle Crost, Nathalie Juge, Edward A Bayer, Harry J Flint
Ruminococcus bromii is a dominant member of the human colonic microbiota that plays a 'keystone' role in degrading dietary resistant starch. Recent evidence from one strain has uncovered a unique cell surface 'amylosome' complex that organizes starch-degrading enzymes. New genome analysis presented here reveals further features of this complex and shows remarkable conservation of amylosome components between human colonic strains from three different continents and a R. bromii strain from the rumen of Australian cattle...
November 21, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/29159586/extensive-hydrolysis-of-raw-rice-starch-by-a-chimeric-%C3%AE-amylase-engineered-with-%C3%AE-amylase-amyp-and-a-starch-binding-domain-from-cryptococcus-sp-s-2
#6
Hui Peng, Rui Li, Fengling Li, Lu Zhai, Xiaohan Zhang, Yazhong Xiao, Yi Gao
Recombinant chimeric α-amylase (AmyP-Cr) was constructed by a catalytic core of α-amylase (AmyP) from a marine metagenomic library and a starch-binding domain (SBDCr) of α-amylase from Cryptococcus sp. S-2. The molecular fusion did not alter optimum pH, optimum temperature, hydrolysis products, and an ability of preferential and rapid degradation towards raw rice starch, but catalytic efficiency and thermostability were remarkably improved compared with those of the wild-type AmyP. AmyP-Cr achieved the final hydrolysis degree of 61...
November 20, 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/29159316/in-vitro-starch-hydrolysis-of-chitosan-incorporating-whey-protein-and-wheat-starch-composite-gels
#7
Natasha Yang, John Ashton, Elisabeth Gorczyca, Stefan Kasapis
The study examined the influence of chitosan, incorporated into whey protein and wheat starch thermo gels, on the in-vitro hydrolysis of the polysaccharide. Gels were subjected to the following external conditions containing α-amylase at constant incubation temperature of 37 °C: In the first procedure, they were immersed in phosphate buffer (0.05 M) and maintained at pH 6.9 throughout the entire digestion. In the second instance, they were introduced into a salt solution, with pH and total volume adjusted at times in sync with the human gastrointestinal tract...
October 2017: Heliyon
https://www.readbyqxmd.com/read/29159143/-grafting-from-synthesis-and-characterization-of-poly-2-ethyl-2-oxazoline-b-poly-benzyl-l-glutamate-micellar-nanoparticles-for-potential-biomedical-applications
#8
Mohsen Salmanpour, Ali Tamaddon, Gholamhossein Yousefi, Soliman Mohammadi-Samani
Introduction: Recent advances in the field of poly (2-oxazolines) as bio-inspired synthetic pseudopeptides have proven their potential biomedical applications such as drug delivery and tissue engineering. Methods: In order to fabricate a biodegradable micellar nanoparticle of poly (2-ethyl 2-oxazoline)-b-poly (benzyl L-glutamate) or pEOx-b-pBLG, "grafting-from" synthesis approach was used involving consecutive steps of cationic ring-opening polymerization of 2-ethyl-2-oxazoline, amine functionalization of pEOx using 1-Boc-piperazine and N-carboxyanhydride polymerization of γ-benzyl- L-glutamate...
2017: BioImpacts: BI
https://www.readbyqxmd.com/read/29159023/8-4-oxyneolignane-glucosides-from-an-aqueous-extract-of-ban-lan-gen-isatis-indigotica-root-and-their-absolute-configurations
#9
Lingjie Meng, Qinglan Guo, Yufeng Liu, Jiangong Shi
Three pairs of glycosidic 8,4'-oxyneolignane diastereoisomers, named isatioxyneolignosides A-F (1-6), were isolated from an aqueous extract of Isatis indigotica roots. Their structures and absolute configurations were elucidated by comprehensive spectroscopic data analysis and enzyme hydrolysis. The validity of ΔδC8-C7 values to distinguish threo and erythro aryl glycerol units and Cotton effects at 235±5 nm to determine absolute configurations at C-8 in 1-6 and their aglycones (1a-6a) are discussed.
November 2017: Acta Pharmaceutica Sinica. B
https://www.readbyqxmd.com/read/29158222/trehalose-metabolism-genes-render-rice-white-tip-nematode-aphelenchoides-besseyi-nematoda-aphelenchoididae-resistant-to-anaerobic-environment
#10
Qiaoli Chen, Feng Wang, Danlei Li, Ruizhi Zhang, Yaming Ling
After experiencing anaerobic environments, Aphelenchoides besseyi will enter a state of suspended animation known as anoxybiosis, which may use trehalose for energy supply to survive. To identify the function of trehalose metabolism, two trehalose-6-phosphate synthase (TPS) genes (Ab-tps1 and Ab-tps2) encoding enzymes catalyzing trehalose synthesis and three trehalase (TRE) genes (Ab-ntre1, Ab-ntre2 and Ab-atre) encoding enzymes catalyzing the hydrolysis of trehalose were identified and investigated. Ab-tps1 and Ab-tps2 were active when A...
November 20, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/29157907/expression-and-purification-of-plant-fructan-exohydrolases-and-their-potential-applications-in-fructose-production
#11
Wenyue Zhan, Lijin Jin, Jiao Jiao, Xi Zhang, Yan Zhang, Haiyan Zhao, Mingxiang Liang
Inulinases from microorganisms have been extensively studied for their role in the production of fructose from fructan. Fructan can also be hydrolyzed by plant fructan exohydrolases (FEHs), but these enzymes have not been used to produce fructose commercially. Two Ht1-FEHs (Ht1-FEH I and Ht1-FEH II) were recently characterized in Jerusalem artichoke. In this study, we cloned the third member of the Ht1-FEH family in Jerusalem artichoke (i.e., Ht1-FEH III). When heterologously expressed in Pichia pastoris X-33, Ht1-FEH III not only demonstrated hydrolysis activity towards β (2, 1)-linked fructans and β (2, 6)-linked levan, but also towards sucrose...
November 17, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/29156236/nanozirconia-supported-ruthenium-0-nanoparticles-highly-active-and-reusable-catalyst-in-hydrolytic-dehydrogenation-of-ammonia-borane
#12
Yalçın Tonbul, Serdar Akbayrak, Saim Özkar
Nanozirconia supported ruthenium(0) nanoparticles (Ru(0)/ZrO2) were prepared by impregnation of ruthenium(III) cations on the surface of zirconia followed by their reduction with sodium borohydride at room temperature. Ru(0)/ZrO2 was isolated from the reaction solution by centrifugation and characterized by ICP-OES, XRD, TEM, SEM-EDS and XPS techniques. All the results reveal that ruthenium(0) nanoparticles were successfully supported on zirconia and the resulting Ru(0)/ZrO2 is a highly active and reusable catalyst for hydrogen generation from the hydrolysis of ammonia borane with a turnover frequency value of 173 min(-1) at 25 °C...
November 13, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/29156090/a-case-control-study-the-association-of-serum-paraoxonase-1-activity-and-concentration-with-the-development-of-type-2-diabetes-mellitus
#13
J Allen Crow, Edward C Meek, Robert W Wills, Janice E Chambers
BACKGROUND: A longitudinal study assessed serum paraoxonase 1 (PON1) activity and concentration as affected by age and as associated with the development of type 2 diabetes (T2D). PON1's recently established physiological function is the hydrolysis of lipolactones in oxidized LDL particles. METHODS: Serum samples and clinical data collected and stored at different time points over a 20 year interval in the Air Force Health Study were analyzed. PON1 activity and concentration and C-reactive protein (CRP) concentration in samples from the same individuals 20 years apart were compared using a paired t test (n=159)...
November 20, 2017: Diabetes/metabolism Research and Reviews
https://www.readbyqxmd.com/read/29155366/applications-of-stimuli-responsive-nanoscale-drug-delivery-systems-in-translational-research
#14
REVIEW
Mengjie Gu, Xin Wang, Tan Boon Toh, Edward Kai-Hua Chow
Nanoscale drug delivery systems or nanocarriers have shown tremendous promise in the target-specific delivery of therapeutics as well as diagnostic agents. Additional properties can be introduced into nanocarriers to enhance the bioavailability and targeting efficiency of the transported drugs at diseased sites. Such nanocarriers are usually incorporated with stimuli-responsive components that can be triggered by specific stimuli (e.g., temperature, pH, or enzymes) and further induced by certain biological responses, such as enzyme hydrolysis and molecular conformational changes, leading to the controlled release of the transported molecules at targeted sites...
November 16, 2017: Drug Discovery Today
https://www.readbyqxmd.com/read/29155329/cloning-and-characterization-of-two-novel-%C3%AE-glucosidase-genes-encoding-isoenzymes-of-the-cellobiase-complex-from-cellulomonas-biazotea
#15
Anthony K N Chan, Alan K L Ng, Kate K Y Ng, W K R Wong
Enzymatic degradation of cellulosic waste to generate renewable biofuels has offered an attractive solution to the energy problem. Synergistic hydrolysis of cellulose residues requires the participation of three different types of cellulases - endoglucanases, exoglucanases, and β-glucosidases (Bgl). Our group has been interested in using Bgl of Cellulomonas biazotea in studies designed to investigate cooperative action among different cellulases. We previously have cloned bgl genes encoding Cba and Cba3, which are C...
November 16, 2017: Gene
https://www.readbyqxmd.com/read/29155297/divergent-profile-between-hypothalamic-and-plasmatic-aminopeptidase-activities-in-wky-and-shr-influence-of-beta-adrenergic-blockade
#16
Isabel Prieto, Ana B Segarra, Marc de Gasparo, Magdalena Martínez-Cañamero, Manuel Ramírez-Sánchez
AIMS: Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) differ in their renin-angiotensin system function and sympathetic tone. The metabolism of angiotensins and vasopressin depends on the action of certain aminopeptidases whose activity may be influenced by the autonomic nervous system. Their regulation may differ between WKY and SHR in hypothalamus and plasma according to the sympathetic tone. We analyzed aminopeptidases responsible for the hydrolysis of certain angiotensins, vasopressin, cholecystokinin or enkephalins in hypothalamus and plasma of WKY and SHR in untreated controls rats and under beta-adrenoceptor blockade...
November 16, 2017: Life Sciences
https://www.readbyqxmd.com/read/29155158/thermodynamic-investigation-of-an-alkaline-protease-from-aspergillus-tamarii-urm4634-a-comparative-approach-between-crude-extract-and-purified-enzyme
#17
Osmar Soares da Silva, Rodrigo Lira de Oliveira, Jonatas de Carvalho Silva, Attilio Converti, Tatiana Souza Porto
The thermostable crude proteolytic extract and purified protease produced by Aspergillus tamarii URM4634 were investigated at different temperatures. The activity results were used to estimate the activation energy of the hydrolysis reaction catalyzed by crude extract and purified protease (E*=34.2 and 16.2kJ/mol) as well as the respective standard enthalpy variations of reversible enzyme unfolding (ΔH°u=31.9 and 13.9kJ/mol). When temperature was raised from 50 to 80°C in residual activity tests, the specific rate constant of crude proteolytic extract thermoinactivation increased from 0...
November 15, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/29155107/structural-insights-of-rmxyn10a-a-prebiotic-producing-gh10-xylanase-with-a-non-conserved-aglycone-binding-region
#18
Anna Aronsson, Fatma Güler, Maxim V Petoukhov, Susan J Crennell, Dmitri I Svergun, Javier A Linares-Pastén, Eva Nordberg Karlsson
Hydrolysis of arabinoxylan (AX) by glycoside hydrolase family 10 (GH10) xylanases produces xylo- and arabinoxylo-oligosaccharides ((A)XOS) which have shown prebiotic effects. The thermostable GH10 xylanase RmXyn10A has shown great potential to produce (A)XOS. In this study, the structure of RmXyn10A was investigated, the catalytic module by homology modelling and site-directed mutagenesis and the arrangement of its five domains by small-angle X-ray scattering (SAXS). Substrate specificity was explored in silico by manual docking and molecular dynamic simulations...
November 14, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/29155085/ir-spectroscopy-analysis-of-pancreatic-lipase-related-protein-2-interaction-with-phospholipids-2-discriminative-recognition-of-various-micellar-systems-and-characterization-of-plrp2-dppc-bile-salt-complexes
#19
Eduardo Mateos-Diaz, Priscila Sutto-Ortiz, Moulay Sahaka, Deborah Byrne, Hélène Gaussier, Frédéric Carrière
The interaction of pancreatic lipase-related protein 2 (PLRP2) with various micelles containing phospholipids was investigated using pHstat enzyme activity measurements, differential light scattering, size exclusion chromatography (SEC) and transmission IR spectroscopy. Various micelles of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and lysophosphatidylcholine were prepared with either bile salts (sodium taurodeoxycholate or glycodeoxycholate) or Triton X-100, which are substrate-dispersing agents commonly used for measuring phospholipase activities...
November 16, 2017: Chemistry and Physics of Lipids
https://www.readbyqxmd.com/read/29154864/hydroxycinnamoylmalated-flavone-c-glycosides-from-lemna-japonica
#20
Huan-Huan Bai, Ni-Ni Wang, Jiao Mi, Tao Yang, Dong-Mei Fang, Lin-Wei Wu, Hai Zhao, Guo-You Li
Three previously undescribed flavone C-glycosides (1-3), along with seven known ones (4-10), were isolated and characterized from the smallest flowering aquatic plant, Lemna japonica. On the basis of spectroscopic analysis and alkaline hydrolysis, compounds 1-3 were identified to be luteolin 6-C-(2″-O-trans-caffeoyl-d-malate)-β-glucoside (1), apigenin 6-C-(2″-O-trans-caffeoyl-d-malate)-β-glucoside (2), and luteolin 6-C-(2″-O-trans-coumaroyl-d-malate)-β-glucoside (3). Compounds 1-3 are characteristic of a trans-coumaroyl-d-malate or trans-caffeoyl-d-malate linked to C-2″ of the glucose, which was reported for the first time...
November 14, 2017: Fitoterapia
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