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https://www.readbyqxmd.com/read/28102767/synthesis-stereochemical-characterization-and-antimicrobial-evaluation-of-a-potentially-nonnephrotoxic-3-c-acethydrazide-puromycin-analog
#1
Josh Carter, Blair A Weaver, Maria A Chiacchio, Amy R Messersmith, Will E Lynch, Brent D Feske, Giuseppe Gumina
Puromycin is a peptidyl nucleoside endowed with significant antibiotic and anticancer properties, but also with an unfortunate nephrotoxic character that has hampered its use as a chemotherapeutic agent. Since hydrolysis of puromycin's amide to puromycin aminonucleoside is the first metabolic step leading to nephrotoxicity, we designed a 3'-C-hydrazide analog where the nitrogen and carbon functionality around the amide carbonyl of puromycin are inverted. The title compound, synthesized in 11 steps from D-xylose, cannot be metabolized to the nephrotoxic aminonucleoside...
January 19, 2017: Nucleosides, Nucleotides & Nucleic Acids
https://www.readbyqxmd.com/read/28102685/direct-assignment-of-the-threo-and-erythro-configurations-in-polyacetylene-glycosides-by-1-h-nmr-spectroscopy
#2
Kuo Xu, Peng-Fei Yang, Ya-Nan Yang, Zi-Ming Feng, Jian-Shuang Jiang, Pei-Cheng Zhang
An approach for discriminating the threo and erythro configurations of polyacetylene glycosides by (1)H NMR spectroscopy was developed. Using acetic acid-d4/D2O as the solvent, a relatively larger (3)JHH value (7.0 Hz) for the acyclic vicinal diol group was unambiguously assigned to the threo configuration, whereas the smaller value (3.5 Hz) was assigned to the erythro configuration. This convenient method requires no hydrolysis or derivatization and is suitable for micromolar concentrations of polyacetylene glycosides...
January 19, 2017: Organic Letters
https://www.readbyqxmd.com/read/28102511/some-nutritional-characteristics-of-enzymatically-resistant-maltodextrin-from-cassava-manihot-esculenta-crantz-starch
#3
Rocío Toraya-Avilés, Maira Segura-Campos, Luis Chel-Guerrero, David Betancur-Ancona
Cassava (Manihot esculenta Crantz) native starch was treated with pyroconversion and enzymatic hydrolysis to produce a pyrodextrin and an enzyme-resistant maltodextrin. Some nutritional characteristics were quantified for both compounds. Pyroconversion was done using a 160:1 (p/v) starch:HCl ratio, 90 °C temperature and 3 h reaction time. The resulting pyrodextrin contained 46.21% indigestible starch and 78.86% dietary fiber. Thermostable α-amylase (0.01%) was used to hydrolyze the pyrodextrin at 95 °C for 5 min...
January 19, 2017: Plant Foods for Human Nutrition
https://www.readbyqxmd.com/read/28101991/clinically-distinct-phenotypes-of-canavan-disease-correlate-with-residual-aspartoacylase-enzyme-activity
#4
Marisa I Mendes, Desirée Ec Smith, Ana Pop, Pascal Lennertz, Matilde R Fernandez Ojeda, Warsha A Kanhai, Silvy J M van Dooren, Yair Anikster, Ivo Barić, Carolien Boelen, Jaime Campistol, Lonneke de Boer, Ariana Kariminejad, Hulya Kayserili, Agathe Roubertie, Krijn T Verbruggen, Christine Vianey-Saban, Monique Williams, Gajja S Salomons
We describe 14 patients with 12 novel missense mutations in ASPA, the gene causing Canavan disease (CD). We developed a method to study the effect of these 12 variants on the function of aspartoacylase - the hydrolysis of N-acetyl-L-aspartic acid (NAA) to aspartate and acetate. The wild-type ASPA open reading frame (ORF) and the ORFs containing each of the variants were transfected into HEK293 cells. Enzyme activity was determined by incubating cell lysates with NAA and measuring the released aspartic acid by LC-MS/MS...
January 19, 2017: Human Mutation
https://www.readbyqxmd.com/read/28101851/importance-of-radioactive-labelling-to-elucidate-inositol-polyphosphate-signalling
#5
REVIEW
Miranda S C Wilson, Adolfo Saiardi
Inositol polyphosphates, in their water-soluble or lipid-bound forms, represent a large and multifaceted family of signalling molecules. Some inositol polyphosphates are well recognised as defining important signal transduction pathways, as in the case of the calcium release factor Ins(1,4,5)P3, generated by receptor activation-induced hydrolysis of the lipid PtdIns(4,5)P2 by phospholipase C. The birth of inositol polyphosphate research would not have occurred without the use of radioactive phosphate tracers that enabled the discovery of the "PI response"...
February 2017: Topics in Current Chemistry (Journal)
https://www.readbyqxmd.com/read/28101787/a-recombinant-highly-thermostable-%C3%AE-mannanase-retman26-from-thermophilic-bacillus-subtilis-tbs2-expressed-in-pichia-pastoris-and-its-ph-and-temperature-stability
#6
Zhangcai Luo, Jing Miao, Guoying Li, Yao Du, Xiaobin Yu
A gene encoding a highly thermostable β-mannanase from a thermophilic Bacillus subtilis (TBS2) was successfully expressed in Pichia pastoris. The maximum activity of the recombinant thermostable β-mannanase (ReTMan26) was 5435 U/mL, which was obtained by high-density, fed-batch cultivation after 168-h induction with methanol in a 50-L bioreactor. The protein yield reached 3.29 mg/mL, and the protein had a molecular weight of ~42 kDa. After fermentation, ReTMan26 was purified using a 10-kDa cut-off membrane and Sephadex G-75 column...
January 18, 2017: Applied Biochemistry and Biotechnology
https://www.readbyqxmd.com/read/28101376/atpase-activity-tightly-regulates-reca-nucleofilaments-to-promote-homologous-recombination
#7
Bailin Zhao, Dapeng Zhang, Chengmin Li, Zheng Yuan, Fangzhi Yu, Shangwei Zhong, Guibin Jiang, Yun-Gui Yang, X Chris Le, Michael Weinfeld, Ping Zhu, Hailin Wang
Homologous recombination (HR), catalyzed in an evolutionarily conserved manner by active RecA/Rad51 nucleofilaments, maintains genomic integrity and promotes biological evolution and diversity. The structures of RecA/Rad51 nucleofilaments provide information critical for the entire HR process. By exploiting a unique capillary electrophoresis-laser-induced fluorescence polarization assay, we have discovered an active form of RecA nucleofilament, stimulated by ATP hydrolysis, that contains mainly unbound nucleotide sites...
2017: Cell Discovery
https://www.readbyqxmd.com/read/28100887/production-of-a-health-beneficial-food-emulsifier-by-enzymatic-partial-hydrolysis-of-phospholipids-obtained-from-the-head-of-autumn-chum-salmon
#8
A K M Azad Shah, Toshihiro Nagao, Hideyuki Kurihara, Koretaro Takahashi
Phospholipids and their partial hydrolysates, namely lysophospholipids (LPLs), have been widely used in food, pharmaceutical, and cosmetic products as highly efficient emulsifiers. This study was conducted to produce docosahexaenoic acid (DHA)-esterified LPLs by enzymatic modification of phospholipids obtained from the head of autumn chum salmon (Oncorhynchus keta). The emulsifying properties of the obtained LPLs were also evaluated. Two different types of substrates of salmon head phospholipids were prepared via silica gel and cold acetone precipitation...
January 18, 2017: Journal of Oleo Science
https://www.readbyqxmd.com/read/28100852/allergenicity-of-milk-of-different-animal-species-in-relation-to-human-milk
#9
Robert Pastuszka, Joanna Barłowska, Zygmunt Litwińczuk
Protein content in cow milk (with over 20 proteins, and peptides may also occur as a result of enzymatic hydrolysis) ranges from 2.5% to 4.2% and is about 1.5-2 times higher than in human milk. Its most important allergens are considered to be β-lactoglobulin (absent in human milk) and αs1-casein. The most similar in composition to human milk is horse and donkey milk. It contains considerably more whey proteins (35-50%) than cow milk (about 20%), and the concentration of the most allergenic casein fraction αs1 is 1...
December 31, 2016: Postȩpy Higieny i Medycyny Doświadczalnej
https://www.readbyqxmd.com/read/28100844/phospholipids-and-products-of-their-hydrolysis-as-dietary-preventive-factors-for-civilization-diseases
#10
Karol Parchem, Agnieszka Bartoszek
The results of numerous epidemiological studies indicate that phospholipids play an important role in the prevention of chronic diseases faced by contemporary society. Firstly, these compounds are responsible for the proper functioning of cell membranes, by ensuring liquidity and permeability, which is pivotal for normal activity of membrane proteins, including receptors. These mechanisms are at the core of prevention of cancer, autoimmune or neurological disorders. Secondly, structure and properties of phospholipids cause that they are highly available source of biologically active fatty acids...
December 31, 2016: Postȩpy Higieny i Medycyny Doświadczalnej
https://www.readbyqxmd.com/read/28100776/crystallographic-snapshots-of-class-a-%C3%AE-lactamase-catalysis-reveal-structural-changes-that-facilitate-%C3%AE-lactam-hydrolysis
#11
Xuehua Pan, Yunjiao He, Jinping Lei, Xuhui Huang, Yanxiang Zhao
β-lactamases confer resistance to β-lactam-based antibiotics. There is great interest in understanding their mechanisms to enable the development of β-lactamase-specific inhibitors. The mechanism of Class A β-lactamases has been studied extensively, revealing Lys73 and Glu166 as general bases that assist the catalytic residue Ser70. However, the specific roles of these two residues within the catalytic cycle remains not fully understood. To help resolve this question, we first identified a Glu166His mutant that is functional but kinetically slowed...
January 18, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28100486/c-jun-enhances-intestinal-epithelial-restitution-after-wounding-by-increasing-phospholipase-c-%C3%AE-1-transcription
#12
Peng-Yuan Wang, Shelley R Wang, Lan Xiao, Jie Chen, Jian-Ying Wang, Jaladanki N Rao
c-Jun is an AP-1 transcription factor and implicated in many aspects of cellular functions, but its exact role in the regulation of early intestinal epithelial restitution after injury remains largely unknown. Phospholipase C-γ1 (PLCγ1) catalyzes hydrolysis of phosphatidylinositol 4,5 biphosphate into the second messenger diacylglycerol and inositol 1,4,5 triphosphate, and coordinates Ca(2+) stores mobilization, and regulates cell migration and proliferation in response to stress. Here we reported that c-Jun up-regulates PLCγ1 expression and enhances PLCγ1-induced Ca(2+) signaling, thus promoting intestinal epithelial restitution after wounding...
January 18, 2017: American Journal of Physiology. Cell Physiology
https://www.readbyqxmd.com/read/28100113/characterization-and-production-of-multifunctional-cationic-peptides-derived-from-rice-proteins
#13
Masayuki Taniguchi, Akihito Ochiai
Food proteins have been identified as a source of bioactive peptides. These peptides are inactive within the sequence of the parent protein and must be released during gastrointestinal digestion, fermentation, or food processing. Of bioactive peptides, multifunctional cationic peptides are more useful than other peptides that have specific activity in promotion of health and/or the treatment of diseases. We have identified and characterized cationic peptides from rice enzymes and proteins that possess multiple functions, including antimicrobial, endotoxin-neutralizing, arginine gingipain-inhibitory, and/or angiogenic activities...
January 19, 2017: Bioscience, Biotechnology, and Biochemistry
https://www.readbyqxmd.com/read/28099989/effects-of-a-dietary-ketone-ester-on-hippocampal-glycolytic-and-tca-cycle-intermediates-and-amino-acids-in-a-3xtgad-mouse-model-of-alzheimer-s-disease
#14
Robert J Pawlosky, Martin F Kemper, Yoshihero Kashiwaya, M Todd King, Mark P Mattson, Richard L Veech
In patients with Alzheimer's disease (AD) and in a triple transgenic (3xTgAD) mouse model of AD low glucose metabolism in the brain precedes loss of memory and cognitive decline. The metabolism of ketones in the brain by-passes glycolysis and therefore may correct several deficiencies that are associated with glucose hypometabolism. A dietary supplement composed of an ester of D-β-hydroxybutyrate and R-1,3 butane diol referred to as ketone ester (KE) was incorporated into a rodent diet and fed to 3xTgAD mice for 8 months...
January 18, 2017: Journal of Neurochemistry
https://www.readbyqxmd.com/read/28099889/evaluation-of-organosolv-pretreatment-on-the-structural-characteristics-of-lignin-polymers-and-follow-up-enzymatic-hydrolysis-of-the-substrates-from-eucalyptus-wood
#15
Bing Wang, Xiao-Jun Shen, Jia-Long Wen, Lin Xiao, Run-Cang Sun
In the present study, Eucalyptus was subjected to organosolv pretreatment processes with aqueous 2-propanol at 200 to 220°C to obtain lignin with benign characters for its valorization and digestible substrates for bioethanol production. Results showed that different delignification ratios (64.00%-81.26%) and molecular weights (Mw=610-2680g/mol) of lignin fractions were dissociated from various pretreatment conditions, and the glucose yields of all the pretreated substrates significantly increased to 54.65-88...
January 15, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28099798/development-of-a-quechers-based-method-for-the-simultaneous-determination-of-acidic-pesticides-their-esters-and-conjugates-following-alkaline-hydrolysis
#16
Angelika Steinborn, Lutz Alder, Madeleine Spitzke, Daniela Doerk, Michelangelo Anastassiades
An analytical procedure was developed allowing the simultaneous determination of acidic pesticides and their conjugates by addition of an alkaline hydrolysis step into the EU version of the QuEChERS method. The procedure resulted additionally in hydrolysis of most esters of phenoxy acids. Based on information from metabolism studies and the hydrolytic conditions employed in supervised field trials as well as results on the influence of physical and chemical parameters (temperature, time, type of solvent, type of matrix) alkaline hydrolysis for 30 min at 40 °C was deemed as a good compromise for the determination of residues of 2,4-D, dichlorprop, fluazifop, haloxyfop, MCPA and MCPB...
January 18, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28099031/stereospecific-intramolecular-arylation-of-2-and-3-pyridyl-substituted-alkylamines-via-configurationally-stable-%C3%AE-pyridyl-organolithiums
#17
Julien Maury, Wojciech Zawodny, Jonathan Clayden
Treatment of N'-aryl urea derivatives of enantiomerically enriched α-(2-pyridyl) and α-(3-pyridyl)alkylamines with a base leads to the migration of the N'-aryl substituent from N to C in a 'nonclassical' intramolecular nucleophilic aromatic substitution reaction. Both electron-rich and -poor rings migrate successfully. A new quaternary stereogenic center is formed adjacent to the pyridine ring with high stereospecificity, even when the intermediate anion is a presumably planar 2-picolyllithium. Base hydrolysis of the urea gives enantiomerically enriched α-pyridylalkylamines...
January 18, 2017: Organic Letters
https://www.readbyqxmd.com/read/28099012/aqueous-photochemistry-of-secondary-organic-aerosol-of-%C3%AE-pinene-and-%C3%AE-humulene-oxidized-with-ozone-hydroxyl-radical-and-nitrate-radical
#18
Dian E Romonosky, Ying Li, Manabu Shiraiwa, Alexander Laskin, Julia Laskin, Sergey A Nizkorodov
Formation of secondary organic aerosols (SOA) from biogenic volatile organic compounds (BVOC) occurs via O3- and OH-initiated reactions during the day and reactions with NO3 during the night. We explored the effect of these three oxidation conditions on the molecular composition and aqueous photochemistry of model SOA prepared from two common BVOC. A common monoterpene, α-pinene, and sesquiterpene, α-humulene, were used to form SOA in a smog chamber via BVOC + O3, BVOC + NO3, and BVOC + OH + NOx oxidation...
January 18, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28098992/mechanistic-insights-into-tunable-metal-mediated-hydrolysis-of-amyloid-%C3%AE-peptides
#19
Jeffrey S Derrick, Jiwan Lee, Shin Jung C Lee, Yujeong Kim, Eunju Nam, Hyeonwoo Tak, Juhye Kang, Misun Lee, Sun Hee Kim, Kiyoung Park, Jaeheung Cho, Mi Hee Lim
An amyloidogenic peptide, amyloid-β (Aβ), has been implicated as a contributor to the neurotoxicity of Alzheimer's disease (AD) that continues to present a major socioeconomic burden for our society. Recently, the use of metal complexes capable of cleaving peptides has arisen as an efficient tactic for amyloid management; unfortunately, little has been reported to pursue this strategy. Herein, we report a novel approach to validate the hydrolytic cleavage of divalent metal complexes toward two major isoforms of Aβ (Aβ40 and Aβ42) and tune their proteolytic activity based on the choice of metal centers (M = Co, Ni, Cu, and Zn) which could be correlated to their anti-amyloidogenic properties...
January 18, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28098943/a-survey-of-the-peptide-profile-in-prato-cheese-as-measured-by-maldi-ms-and-capillary-electrophoresis
#20
Débora Parra Baptista, Francisca Diana da Silva Araújo, Marcos Nogueira Eberlin, Mirna Lúcia Gigante
In this study, we describe the characterization of the peptide profile in commercial Prato cheese by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) and capillary electrophoresis (CE). Ten commercial Prato cheese brands were characterized via their physicochemical composition and subjected to fractionation according to solubility at pH 4.6. The pH 4.6 insoluble fraction was evaluated by CE, whereas MALDI-MS was applied to the fraction soluble at pH 4.6 and in 70% ethanol. CE revealed a characteristic pattern of hydrolysis, with formation of para-κ-casein, hydrolysis of αs1 -casein at the Phe23 - Phe24 bond, and hydrolysis of β-casein...
January 18, 2017: Journal of Food Science
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