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https://www.readbyqxmd.com/read/28637348/hydrogen-peroxide-sensing-based-on-inner-surfaces-modification-of-solid-state-nanopore
#1
Libo Zhu, Dejian Gu, Quanjun Liu
There are many techniques for the detection of molecules. But detection of molecules through solid-state nanopore in a solution is one of the promising, high-throughput, and low-cost technology used these days. In the present investigation, a solid-state nanopore platform was fabricated for the detection of hydrogen peroxide (H2O2), which is not only a label free product but also a significant participant in the redox reaction. We have successfully fabricated silicon nitride (Si3N4) nanopores with diameters of ~50 nm by using a focused Ga ion beam, the inner surface of the nanopore has been modified with horseradish peroxidase (HRP) by employing carbodiimide coupling chemistry...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28637339/emergence-of-ceftazidime-avibactam-non-susceptibility-in-an-mdr-klebsiella-pneumoniae-isolate
#2
Anna Both, Henning Büttner, Jiabin Huang, Markus Perbandt, Cristina Belmar Campos, Martin Christner, Florian P Maurer, Stefan Kluge, Christina König, Martin Aepfelbacher, Dominic Wichmann, Holger Rohde
Background: Avibactam is a novel broad-range β-lactamase inhibitor active against Ambler class A (including ESBL and KPC) and some Ambler class C and D (e.g. OXA-48) enzymes. We here report on the emergence of ceftazidime/avibactam resistance in clinical, multiresistant, OXA-48 and CTX-M-14-producing Klebsiella pneumoniae isolate DT12 during ceftazidime/avibactam treatment. Methods and results: Comparative whole-genome sequence analysis identified two SNPs in the CTX-M-14-encoding gene leading to two amino acid changes (P170S and T264I)...
June 16, 2017: Journal of Antimicrobial Chemotherapy
https://www.readbyqxmd.com/read/28637331/antioxidants-as-stabilizers-for-his6-oph-is-this-an-unusual-or-regular-role-for-them-with-enzymes
#3
Elena N Efremenko, Ilya V Lyagin, Le Huu Cuong, Le Mai Huong
HASH(0x4287320)
June 16, 2017: Journal of Biochemistry
https://www.readbyqxmd.com/read/28637330/occurrence-of-aminoglycoside-modifying-enzymes-ames-among-isolates-of-escherichia-coli-exhibiting-high-levels-of-aminoglycoside-resistance-isolated-from-korean-cattle-farms
#4
Kuastros Mekonnen Belaynehe, Seung Won Shin, Park Hong-Tae, Han Sang Yoo
This study investigated 247 Escherichia coli isolates collected from four cattle farms to characterize aminoglycoside-modifying enzyme (AME) genes, their plasmid replicons and transferability. Out of 247 isolates a high number of isolates (total 202; 81.78%) were found resistant to various antibiotics by disc-diffusion. Of the 247 strains 139 (56.3%) were resistant to streptomycin and other antibiotics resistance followed as tetracycline (12.15%), ampicillin (7%), chloramphenicol (5.7%) and trimethoprim-sulfamethoxazole (0...
June 15, 2017: FEMS Microbiology Letters
https://www.readbyqxmd.com/read/28637295/inhibition-of-polyamine-synthesis-causes-entry-of-the-mouse-blastocyst-into-embryonic-diapause1
#5
Jane C Fenelon, Bruce D Murphy
Embryonic diapause is a common reproductive strategy amongst mammals, requiring an intimate cross-talk between the endometrium and the blastocyst. To date, the precise molecular signals responsible are unknown in the mouse or any other mammal. Previous studies in the mink implicate polyamines as major regulators of the control of diapause. In the mouse, inhibiting the rate-limiting enzyme of polyamine synthesis, ornithine decarboxylase (ODC1) during early pregnancy largely prevents implantation, but the fate of the non-implanted embryos is unknown...
June 16, 2017: Biology of Reproduction
https://www.readbyqxmd.com/read/28637248/expression-and-comparison-of-codon-optimised-aspergillus-tubingensis-amylase-variants-in-saccharomyces-cerevisiae
#6
Rosemary A Cripwell, Shaunita H Rose, Willem H van Zyl
The expression of codon optimised genes is a popular genetic engineering approach for the production of industrially relevant proteins. This study investigates and compares the expression of codon optimised and codon adapted amylase variants. The Aspergillus tubingensis raw starch hydrolysing α-amylase (amyA) and glucoamylase (glaA) encoding genes were redesigned using synonymous codons and expressed in S. cerevisiae Y294. Codon optimisation to favour S. cerevisiae codon bias resulted in a decrease in extracellular enzyme activity of 72% (30...
June 15, 2017: FEMS Yeast Research
https://www.readbyqxmd.com/read/28637217/experimental-support-that-natural-selection-has-shaped-the-latitudinal-distribution-of-mitochondrial-haplotypes-in-australian-drosophila-melanogaster
#7
M Florencia Camus, Jonci N Wolff, Carla M Sgrò, Damian K Dowling
Cellular metabolism is regulated by enzyme complexes within the mitochondrion, the function of which are sensitive to the prevailing temperature. Such thermal sensitivity, coupled with the observation that population frequencies of mitochondrial haplotypes tend to associate with latitude, altitude or climatic regions across species distributions, led to the hypothesis that thermal selection has played a role in shaping standing variation in the mitochondrial DNA (mtDNA) sequence. This hypothesis, however, remains controversial, and requires evidence that the distribution of haplotypes observed in nature corresponds with the capacity of these haplotypes to confer differences in thermal tolerance...
June 20, 2017: Molecular Biology and Evolution
https://www.readbyqxmd.com/read/28637181/crosstalk-between-histone-modifications-indicates-that-inhibition-of-arginine-methyltransferase-carm1-activity-reverses-hiv-latency
#8
Zheng Zhang, Bryan C Nikolai, Leah A Gates, Sung Yun Jung, Edward B Siwak, Bin He, Andrew P Rice, Bert W O'Malley, Qin Feng
In eukaryotic cells, the gene expression status is strictly controlled by epigenetic modifications on chromatin. The repressive status of chromatin largely contributes to HIV latency. Studies have shown that modification of histone H3K27 acts as a key molecular switch for activation or suppression of many cellular genes. In this study, we found that K27-acetylated histone H3 specifically recruited Super Elongation Complex (SEC), the transcriptional elongation complex essential for HIV-1 long terminal repeat (LTR)-mediated and general cellular transcription...
June 20, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28637167/effects-of-dissolved-oxygen-concentration-on-photosynthetic-bacteria-wastewater-treatment-pollutants-removal-cell-growth-and-pigments-production
#9
Fan Meng, Anqi Yang, Guangming Zhang, Hangyao Wang
Dissolved oxygen (DO) is an important parameter in photosynthetic bacteria (PSB) wastewater treatment. This study set different DO levels and detected the pollutants removal, PSB growth and pigments production. Results showed that DO significantly influenced the performances of PSB wastewater treatment process. The highest COD (93%) and NH3-N removal (83%) was achieved under DO of 4-8mg/L, but DO of 2-4mg/L was recommended considering the aeration cost. PSB biomass reached 1645mg/L under DO of 4-8mg/L with satisfying co-enzyme Q10 content...
June 1, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28637087/deleting-pck-improves-growth-and-suppresses-by-product-formation-during-1-3-propanediol-fermentation-by-klebsiella-pneumoniae
#10
Yongqiang Zhang, Zongxiao Ji, Jie Lin, Danfeng Xu, Shuilin Fu, Heng Gong
AIMS: To investigate the role of phosphoenolpyruvate (PEP) carboxylation in cell metabolism in Klebsiella pneumoniae. METHODS AND RESULTS: The effects of deleting pck, which encodes PEP carboxykinase (PCK), and/or ppc, which encodes PEP carboxylase (PPC), on growth, enzyme activity, and metabolite formation of K. pneumoniae were investigated. A self-regulatory mechanism of PEP carboxylation was found in ppc- or pck-deficient mutants, which resulted in almost no change of succinate formation...
June 21, 2017: Journal of Applied Microbiology
https://www.readbyqxmd.com/read/28637041/the-effects-of-fungicides-on-human-3%C3%AE-hydroxysteroid-dehydrogenase-1-and-aromatase-in-human-placental-cell-line-jeg-3
#11
Shuyan Cao, Leping Ye, Ying Wu, Baiping Mao, Lanlan Chen, Xiudi Wang, Ping Huang, Ying Su, Ren-Shan Ge
Placenta secretes a large amount of progesterone and estradiol, which are critical for maintaining pregnancy. In human placenta, 3β-hydroxysteroid dehydrogenase 1 (HSD3B1) catalyzes pregnenolone to form progesterone, and aromatase (CYP19A1) catalyzes testosterone into estradiol. Fungicides display antifungal activities and are widely used to prevent fungal infections in agricultural plants. These chemicals include azoles, such as tebuconazole (TEB), triadimefon (TRI), and vinclozolin (VCZ) or organotins, such as tributyltin (TBT) and tetrabutyltin (TTBT)...
June 22, 2017: Pharmacology
https://www.readbyqxmd.com/read/28636949/cloning-expression-and-nutritional-regulation-of-the-glutamine-synthetase-gene-in-ctenopharyngodon-idellus
#12
Rong Hu, Fufa Qu, Jianzhou Tang, Qiong Zhao, Jinpeng Yan, Zhigang Zhou, Yi Zhou, Zhen Liu
Glutamine synthetase (GS) is considered a master enzyme that catalyses ATP-dependent biosynthesis of glutamine from glutamate. In the present study, the GS gene was cloned from the intestine of grass carp, (Ctenopharyngodon idellus). The full-length cDNA sequence of GS encodes a 371-amino-acid polypetide. Phylogenetic analysis of the C. idellus GS sequence reveals common carp (Cyprinus carpio) as its closest neighbor. GS mRNA was differentially expressed in different tissues, with high to low gradient expression the intestine, brain, muscle, heart, gill, liver, pituitary gland, and spleen...
June 18, 2017: Comparative Biochemistry and Physiology. Part B, Biochemistry & Molecular Biology
https://www.readbyqxmd.com/read/28636934/the-tmao-producing-enzyme-flavin-containing-monooxygenase-3-regulates-obesity-and-the-beiging-of-white-adipose-tissue
#13
Rebecca C Schugar, Diana M Shih, Manya Warrier, Robert N Helsley, Amy Burrows, Daniel Ferguson, Amanda L Brown, Anthony D Gromovsky, Markus Heine, Arunachal Chatterjee, Lin Li, Xinmin S Li, Zeneng Wang, Belinda Willard, YongHong Meng, Hanjun Kim, Nam Che, Calvin Pan, Richard G Lee, Rosanne M Crooke, Mark J Graham, Richard E Morton, Carl D Langefeld, Swapan K Das, Lawrence L Rudel, Nizar Zein, Arthur J McCullough, Srinivasan Dasarathy, W H Wilson Tang, Bernadette O Erokwu, Chris A Flask, Markku Laakso, Mete Civelek, Sathyamangla V Naga Prasad, Joerg Heeren, Aldons J Lusis, Stanley L Hazen, J Mark Brown
Emerging evidence suggests that microbes resident in the human intestine represent a key environmental factor contributing to obesity-associated disorders. Here, we demonstrate that the gut microbiota-initiated trimethylamine N-oxide (TMAO)-generating pathway is linked to obesity and energy metabolism. In multiple clinical cohorts, systemic levels of TMAO were observed to strongly associate with type 2 diabetes. In addition, circulating TMAO levels were associated with obesity traits in the different inbred strains represented in the Hybrid Mouse Diversity Panel...
June 20, 2017: Cell Reports
https://www.readbyqxmd.com/read/28636912/channeling-of-camp-in-pde-pka-complexes-promotes-signal-adaptation
#14
Nikhil Kumar Tulsian, Srinath Krishnamurthy, Ganesh Srinivasan Anand
Spatiotemporal control of the cAMP signaling pathway is governed by both hormonal stimulation of cAMP generation by adenylyl cyclases (activation phase) and cAMP hydrolysis by phosphodiesterases (PDEs) (termination phase). The termination phase is initiated by PDEs actively targeting the protein kinase A (PKA) R-subunit through formation of a PDE-PKAR-cyclic adenosine monophosphate (cAMP) complex (the termination complex). Our results using PDE8 as a model PDE, reveal that PDEs mediate active hydrolysis of cAMP bound to its receptor RIα by enhancing the enzymatic activity...
June 20, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28636911/direct-conversion-of-an-enzyme-from-native-like-to-amyloid-like-aggregates-within-inclusion-bodies
#15
Francesco Elia, Francesca Cantini, Fabrizio Chiti, Christopher Martin Dobson, Francesco Bemporad
The acylphosphatase from Sulfolobus solfataricus (Sso AcP) is a globular protein able to aggregate in vitro from a native-like conformational ensemble without the need for a transition across the major unfolding energy barrier. This process leads to the formation of assemblies in which the protein retains its native-like structure, which subsequently convert into amyloid-like aggregates. Here, we investigate the mechanism by which Sso AcP aggregates in vivo to form bacterial inclusion bodies after expression in E...
June 20, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28636885/differential-changes-in-the-pharmacokinetics-of-statins-in-collagen-induced-arthritis-rats
#16
Chun-Han Lin, Ke-Wei Hsu, Chia-Hao Chen, Yow-Shieng Uang, Chun-Jung Lin
The elevated systemic levels of cytokines in rheumatoid arthritis (RA) can change the expression of metabolic enzymes and transporters. Given that statins are lipid-lowering agents frequently used in RA patients with concurrent cardiovascular diseases, the objective of the present study was to investigate the impacts of RA on the pharmacokinetics of statins of different disposition properties in rats with collagen-induced arthritis (CIA). The expression of metabolic enzymes and transporters in tissues of CIA rats were analyzed by RT-qPCR...
June 18, 2017: Biochemical Pharmacology
https://www.readbyqxmd.com/read/28636878/lycium-barbarum-polysaccharide-alleviates-nonylphenol-exposure-induced-testicular-injury-in-juvenile-zebrafish
#17
Ze-Yong Tang, Dong Sun, Chun-Wei Qian, Qi Chen, Shun-Shan Duan, Sheng-Yun Sun
Nonylphenol is an endocrine disrupting chemicals that can disrupt the organisms' reproductive system, and exists widely in rivers and lakes. Lycium barbarum polysaccharide (LBP) is the main active constituent (about 10%) in Lycium barbarum, which is used to protect reproductive health. In this study, we investigated whether LBP can alleviate nonylphenol exposure induced testicular injury in juvenile zebrafish. We detected histological alteration, anti-oxidant enzyme profile and P450 gene transcription to assess LBP effect on testicular development...
June 18, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28636874/next-generation-matrix-metalloproteinase-inhibitors-novel-strategies-bring-new-prospects
#18
REVIEW
Maxim Levin, Yael Udi, Inna Solomonov, Irit Sagi
Enzymatic proteolysis of cell surface proteins and extracellular matrix (ECM) is critical for tissue homeostasis and cell signaling. These proteolytic activities are mediated predominantly by a family of proteases termed matrix metalloproteinases (MMPs). The growing evidence in recent years that ECM and non-ECM bioactive molecules (e.g., growth factors, cytokines, chemokines, on top of matrikines and matricryptins) have versatile functions redefines our view on the roles matrix remodeling enzymes play in many physiological and pathological processes, and underscores the notion that ECM proteolytic reaction mechanisms represent master switches in the regulation of critical biological processes and govern cell behavior...
June 18, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28636837/microrna-101-2-5p-targets-the-apob-gene-in-liver-of-chicken-gallus-gallus
#19
Zheng Ma, Hong Li, Hang Zheng, Keren Jiang, Lijuan Jia, Fengbin Yan, Yadong Tian, Xiangtao Kang, Yanbin Wang, Xiaojun Liu
Apolipoprotein B (ApoB) is a major protein component of plasma lipoproteins, which have been involved in many important biological processes such as lipid transportation, enzyme activity regulation and receptor recognition. Extensive studies have showed that the expression of the ApoB was regulated at multiple levels. However, the regulation of ApoB expression by microRNAs (miRNAs) still remains unknown. In present studies, miRNAs that interact with ApoB have been predicted in chicken. The targeted relationship between the predicated miRNAs and ApoB was verified through dual luciferase reporter assay in chicken DF1 cells, and the effect of miRNAs on ApoB expression was analyzed in chicken embryo hepatocytes stimulated by 17β-estradiol...
June 21, 2017: Genome Génome / Conseil National de Recherches Canada
https://www.readbyqxmd.com/read/28636806/ph-dependent-general-base-catalyzed-activation-rather-than-isocyanate-liberation-may-explain-the-superior-anticancer-efficacy-of-laromustine-compared-to-related-1-2-bis-methylsulfonyl-1-2-chloroethyl-hydrazine-prodrugs
#20
P G Penketh, R A Finch, R Sauro, R P Baumann, E S Ratner, K Shyam
Laromustine (also known as cloretazine, onrigin, VNP40101M, 101M) is a prodrug of 90CE, a short-lived chloroethylating agent with anticancer activity. The short half-life of 90CE necessitates the use of latentiated prodrug forms for in vivo treatments. Alkylaminocarbonyl based prodrugs such as laromustine exhibit significantly superior in vivo activity in several murine tumor models compared to analogs utilizing acyl, and alkoxycarbonyl latentiating groups. The alkylaminocarbonyl prodrugs possess two exclusive characteristics: (i) they are primarily unmasked by spontaneous base catalyzed elimination; and (ii) they liberate a reactive carbamoylating species...
June 21, 2017: Chemical Biology & Drug Design
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