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https://www.readbyqxmd.com/read/28109047/novel-antiplatelet-role-for-a-protein-disulfide-isomerase-targeted-peptide-evidence-of-covalent-binding-to-c-terminal-cghc-redox-motif
#1
H R Sousa, R S Gaspar, E M L Sena, S A da Silva, J L de L Fontelles, T L S Araújo, M Mastrogiovanni, D M Fries, A P S Azevedo-Santos, F R M Laurindo, A Trostchansky, A M Paes
Protein disulfide isomerase (PDI) plays a major role in platelet aggregation and its inhibitors have emerged as novel antithrombotic drugs. In previous work, we designed a peptide based on PDI redox motif (CGHC) that inhibited both PDI reductase activity and PDI-modulated superoxide generation by neutrophil Nox2. Thus, we hypothesized this peptide would also inhibit platelet aggregation by association to surface PDI. Three peptides were used: CxxC, containing the PDI redox motif; Scr, presenting a scrambled sequence of the same residues and AxxA, with cysteines replaced by alanine...
January 21, 2017: Journal of Thrombosis and Haemostasis: JTH
https://www.readbyqxmd.com/read/28108916/oxidation-of-danofloxacin-by-free-chlorine-kinetic-study-structural-identification-of-by-products-by-lc-ms-ms-and-potential-toxicity-of-by-products-using-in-silico-test
#2
Montaha Yassine, Ahmad Rifai, Samah Doumyati, Aurélien Trivella, Patrick Mazellier, Hélène Budzinski, Mohamad Al Iskandarani
: In this study, we aimed to investigate the kinetics and the mechanism of reaction of the fluoroquinolone antibacterial danofloxacin (DANO) by free available chlorine (FAC) during water chlorination process. Kinetic study was thus performed at pH 7.2, 20 °C in the presence of an excess of total chlorine. Under these experimental conditions, a second-order reaction rate constant (first-order relative to DANO concentration and first-order relative to FAC concentration) was evaluated to k~1446 M(-1) s(-1)...
January 20, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28108250/synthesis-of-vorinostat-and-cholesterol-conjugate-to-enhance-the-cancer-cell-uptake-selectivity
#3
Nethrie D Idippily, Chunfang Gan, Paul Orefice, Jane Peterson, Bin Su
Histone deacetylase (HDAC) inhibitors modulate various cellular functions including proliferation, differentiation, and apoptosis. Vorinostat (SuberAniloHydroxamic Acid, SAHA) is the first HDAC inhibitor approved by FDA for cancer treatment. However, SAHA distributes in cancer tissue and normal tissue in similar levels. It will be ideal to selectively deliver SAHA into cancer cells. Rapidly growing cancer cells have a great need of cholesterol. Low-density lipoprotein (LDL) is the major cholesterol carrier in plasma and its uptake is mediated by LDL-receptor (LDL-R), a glycoprotein overexpressed on the surface of cancer cells...
January 10, 2017: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/28108197/identification-of-aminopeptidase-n2-as-a-cry2ab-binding-protein-in-manduca-sexta
#4
Janette Onofre, Meztlli O Gaytán, Arlen Peña-Cardeña, Blanca I García-Gomez, Sabino Pacheco, Isabel Gómez, Alejandra Bravo, Mario Soberón
Bacillus thuringiensis Cry2Ab toxin has been used in combination with Cry1Ac for resistance management on the Bt-cotton that is widely planted worldwide. However, little is known regarding Cry2Ab mode of action. Particularly, there is a gap of knowledge on the identification of insect midgut proteins that bind Cry2Ab and mediate toxicity. In the case of Cry1Ab toxin, a transmembrane cadherin protein and glycosyl-phosphatidylinositol (GPI) anchored proteins like aminopeptidase-N1 (APN1) or alkaline-phosphatase (ALP) from Manduca sexta, have been shown to be important for oligomer formation and insertion into the membrane...
January 17, 2017: Peptides
https://www.readbyqxmd.com/read/28107999/determination-of-sulfonamides-in-animal-tissues-by-modified-quechers-and-liquid-chromatography-tandem-mass-spectrometry
#5
Ching-Hsuan Wen, Shu-Ling Lin, Ming-Ren Fuh
In this study, the salting-out solvent extraction and dispersive solid-phase extraction (dSPE) clean-up steps in QuEChERS (quick, easy, cheap, effective, rugged, and safe) method were optimized to reduce matrix effect and efficiently extract target sulfonamides from a variety of edible animal tissues. The extracted sulfonamides were then analyzed using liquid chromatography tandem mass spectrometry (LC-MS/MS). Good extraction recoveries (74.0-100.3% in five different sources of animal tissues; n=3) with acceptable matrix effect (<10%, except for liver samples) were obtained using the proposed method...
March 1, 2017: Talanta
https://www.readbyqxmd.com/read/28107975/comparison-of-sample-preparation-strategies-for-target-analysis-of-total-thyroid-hormones-levels-in-serum-by-liquid-chromatography-quadrupole-time-of-flight-mass-spectrometry
#6
E Álvarez, Y Madrid, M D Marazuela
This paper describes a novel method based on liquid chromatography quadrupole time-of-flight-mass spectrometry (LC-QTOF-MS) for target analysis of total THs in serum. Several sample preparation strategies have been evaluated to reduce matrix effect (namely, HybridSPE cartridges, supported liquid extraction, SLE and solid phase extraction, SPE). Deproteinization and further clean-up with mixed-mode SPE was selected as the best strategy for sample preparation, since achieved the cleanest extracts and reduced ionization suppression effects (between -11 and -24%)...
March 1, 2017: Talanta
https://www.readbyqxmd.com/read/28107906/development-of-data-independent-acquisition-workflows-for-metabolomic-analysis-on-a-quadrupole-orbitrap-platform
#7
Juntuo Zhou, Yuhua Li, Xi Chen, Lijun Zhong, Yuxin Yin
Untargeted metabolomic profiling has been widely used in recent years. However, the low reproducibility of the data-dependent acquisition (DDA) strategy presents a major bottleneck that considerably limits the reliability of metabolomic studies in biological and clinical research. The data-independent acquisition (DIA) strategy is proposed to solve the above-mentioned problem, and it is gaining popularity. This paper presents a novel approach for performing metabolomic analysis using an untargeted, liquid chromatography-data independent-mass spectrometry (LC-DIA-MS) strategy on a quadrupole-Orbitrap platform...
March 1, 2017: Talanta
https://www.readbyqxmd.com/read/28107701/simultaneous-determination-of-amantadine-rimantadine-and-memantine-in-processed-products-chicken-tissues-and-eggs-by-liquid-chromatography-with-tandem-mass-spectrometry
#8
Yumi Tsuruoka, Takayuki Nakajima, Maki Kanda, Hiroshi Hayashi, Yoko Matsushima, Souichi Yoshikawa, Marie Nagata, Hiroshi Koike, Chieko Nagano, Kotaro Sekimura, Tsuneo Hashimoto, Ichiro Takano, Tetsuya Shindo
A simultaneous determination of amantadine, rimantadine, and memantine in processed products (deep-fried chicken, fried chicken, fried quail egg, and grilled chicken) with liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed. This new method was also applicable for chicken tissue (muscle, liver, and gizzard) and eggs. The chromatographic separation was performed on a Kinetex(®) XB-C18 core-shell technology column using a mobile phase of acetonitrile and 0.1% formic acid in a 10mmol/L ammonium formate solution, resulting in the complete separation of isomers (rimantadine and memantine) and any other obstructive peaks from the sample matrices...
January 11, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28107699/analysis-of-n-nitrosonornicotine-enantiomers-in-human-urine-by-chiral-stationary-phase-liquid-chromatography-nanoelectrospray-ionization-high-resolution-tandem-mass-spectrometry
#9
Jing Yang, Steven G Carmella, Stephen S Hecht
We have developed a chiral stationary phase liquid chromatography-nanoelectrospray ionization-high resolution tandem mass spectrometry (LC-NSI-HRMS/MS) method to investigate the enantiomeric composition of low parts per trillion amounts of the carcinogen N'-nitrosonornicotine (NNN) in the urine of cigarette smokers and smokeless tobacco users. (S)-NNN is the major enantiomer in tobacco and is more carcinogenic than (R)-NNN in rats, but no data are available on the enantiomeric composition of NNN in humans. The method used [(13)C6]NNN as an internal standard and [pyridine-D4]nornicotine to monitor possible artifactual formation of NNN, which was found to be less than 2% of the quantified NNN...
January 9, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28107630/2-o-methyl-5-hydroxymethylcytidine-a-second-oxidative-derivative-of-5-methylcytidine-in-rna
#10
Sabrina M Huber, Pieter van Delft, Arun A Tanpure, Eric A Miska, Shankar Balasubramanian
5-hydroxymethylcytidine (hm5C) was recently identified as a direct metabolite of m5C in RNA. We investigated the stability of hm5C in human cells using bio-isotopomers and high-resolution tandem LC-MS/MS. This has led to the discovery of a second oxidative metabolite of m5C in RNA, namely 2'-O-methyl-5-hydroxymethylcytidine (hm5Cm). Subsequent quantitative analysis of total RNA from higher organisms, revealed varying levels and TET-independent formation of this new RNA modification.
January 20, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28107170/hb-variants-in-korea-effect-on-hba1c-using-five-routine-methods
#11
Yeo-Min Yun, Misuk Ji, Dae-Hyun Ko, Sail Chun, Gye Cheol Kwon, Kyunghoon Lee, Sang Hoon Song, Moon Woo Seong, Sung Sup Park, Junghan Song
BACKGROUND: Quantification of glycated hemoglobin (HbA1c) is a challenge in patients with hemoglobin (Hb) variants. We evaluated the impact of various Hb variants on five routine HbA1c assays by comparing with the IFCC reference measurement procedure (RMP). METHODS: Whole blood samples showing warning flags or no results on routine HPLC HbA1c assays were confirmed for Hb variants and were submitted to HbA1c quantification using Sebia Capillarys 2 Flex Piercing, Roche Tina-quant HbA1c Gen...
January 20, 2017: Clinical Chemistry and Laboratory Medicine: CCLM
https://www.readbyqxmd.com/read/28107167/activity-of-the-liver-enzyme-ornithine-carbamoyltransferase-otc-in-blood-lc-ms-ms-assay-for-non-invasive-diagnosis-of-ornithine-carbamoyltransferase-deficiency
#12
Jakub Krijt, Jitka Sokolová, Pavel Ješina, Lenka Dvořáková, Martin Řeboun, Katarína Brennerová, Martin Mistrík, Jiří Zeman, Tomáš Honzík, Viktor Kožich
BACKGROUND: Liver enzymes are released from hepatocytes into circulation and their activity can be measured in the blood. We examined whether the plasma activity of the liver enzyme ornithine carbamoyltransferase, determined by a novel liquid chromatography-mass spectrometry (LC-MS/MS) assay, could be utilized for the detection of OTC deficiency (OTCD), an X-linked inborn error of the urea cycle. METHODS: The plasma ornithine carbamoyltransferase (OTC) activity was assayed in the reverse reaction using isotopically labeled citrulline-d4 as a substrate and by determination of the product, ornithine-d4, by LC-MS/MS analysis...
January 20, 2017: Clinical Chemistry and Laboratory Medicine: CCLM
https://www.readbyqxmd.com/read/28107105/optimised-deconjugation-of-androgenic-steroid-conjugates-in-bovine-urine
#13
Mikael Pedersen, Henrik L Frandsen, Jens H Andersen
After administration of steroids to animals the steroids are partially metabolised in the liver and kidney to phase 2 metabolites, i.e., glucuronic acid or sulphate conjugates. During analysis these conjugated metabolites are normally deconjugated enzymatically with aryl sulphatase and glucuronidase resulting in free steroids in the extract. It is well known that some sulphates are not deconjugated using aryl sulphatase; instead, for example, solvolysis can be used for deconjugation of these aliphatic sulphates...
January 20, 2017: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
https://www.readbyqxmd.com/read/28107008/robust-sensitive-and-automated-phosphopeptide-enrichment-optimized-for-low-sample-amounts-applied-to-primary-hippocampal-neurons
#14
Harm Post, Renske Penning, Martin A Fitzpatrick, Luc B Garrigues, W Wu, Harold D MacGillavry, Casper C Hoogenraad, Albert J R Heck, A F Maarten Altelaar
Because of the low stoichiometry of protein phosphorylation, targeted enrichment prior to LC-MS/MS analysis is still essential. The trend in phosphoproteome analysis is shifting toward an increasing number of biological replicates per experiment, ideally starting from very low sample amounts, placing new demands on enrichment protocols to make them less labor-intensive, more sensitive, and less prone to variability. Here we assessed an automated enrichment protocol using Fe(III)-IMAC cartridges on an AssayMAP Bravo platform to meet these demands...
December 6, 2016: Journal of Proteome Research
https://www.readbyqxmd.com/read/28106740/chemical-composition-and-antioxidant-properties-of-powders-obtained-from-different-plum-juice-formulations
#15
Anna Michalska, Aneta Wojdyło, Grzegorz P Łysiak, Adam Figiel
Among popular crops, plum (Prunus domestica L.) has received special attention due to its health-promoting properties. The seasonality of this fruit makes it impossible to consume it throughout the year, so new products in a powder form may offer an alternative to fresh consumption and may be used as high-quality natural food ingredients. A 100% plum (cultivar "Valor") juice was mixed with three different concentrations of maltodextrin or subjected to sugars removal by amberlite-XAD column, and dried using the freeze, spray, and vacuum (40, 60, and 80 °C) drying techniques...
January 17, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28106476/quantification-of-hepcidin-25-in-human-cerebrospinal-fluid-using-lc-ms-ms
#16
Constance Delaby, Pauline Bros, Jérôme Vialaret, Amandine Moulinier, Vincent Delatour, Audrey Gabelle, Sylvain Lehmann, Christophe Hirtz
AIM: Hepcidin, the main iron metabolism regulator, can be detected in various biological fluids. Here, we describe a quantitative method of LC-MS/MS to quantify the 25 amino acid isoform of hepcidin (hepcidin-25) in human cerebrospinal fluid (CSF). Results & methodology: Samples were prepared through protein precipitation followed by solid phase extraction (SPE) and injected into a triple-quadrupole mass spectrometer. Validation of our method included determination of LOQ (0.1 ng/ml), repeatability, intermediate precision, recovery and linearity (up to 25 ng/ml)...
January 20, 2017: Bioanalysis
https://www.readbyqxmd.com/read/28105858/hplc-ms-ms-method-for-dexmedetomidine-quantification-with-design-of-experiments-approach-application-to-pediatric-pharmacokinetic-study
#17
Oliwia Szerkus, Wiktoria Struck-Lewicka, Marta Kordalewska, Ewa Bartosińska, Renata Bujak, Agnieszka Borsuk, Agnieszk Bienert, Alicja Bartkowska-Śniatkowska, Justyna Warzybok, Paweł Wiczling, Antoni Nasal, Roman Kaliszan, Mchał Jan Markuszewski, Danuta Siluk
AIM: The purpose of this work was to develop and validate a rapid and robust LC-MS/MS method for the determination of dexmedetomidine (DEX) in plasma, suitable for analysis of a large number of samples. METHOD: Systematic approach, Design of Experiments, was applied to optimize ESI source parameters and to evaluate method robustness, therefore, a rapid, stable and cost-effective assay was developed. The method was validated according to US FDA guidelines. LLOQ was determined at 5 pg/ml...
January 20, 2017: Bioanalysis
https://www.readbyqxmd.com/read/28105847/compact-ultrahigh-pressure-nanoflow-capillary-liquid-chromatograph
#18
Xiaofeng Zhao, Xiaofeng Xie, Sonika Sharma, Luke T Tolley, Alex Plistil, Hal E Barnett, Martin P Brisbin, Adam C Swensen, John C Price, Paul B Farnsworth, H Dennis Tolley, Stanley D Stearns, Milton L Lee
A compact ultrahigh-pressure nanoflow liquid chromatograph (LC) was developed with the purpose in mind of creating a portable system that could be easily moved to various testing locations or placed in close proximity to other instruments for optimal coupling, such as with mass spectrometry (MS). The system utilized innovative nanoflow pumps integrated with a very low volume stop-flow injector and mixing tee. The system weighed only 5.9 kg (13 lbs) or 4.5 kg (10 lbs) without a controller and could hold up to 1100 bar (16000 psi) of pressure...
January 3, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28105593/monitoring-pharmaceuticals-and-personal-care-products-in-reservoir-water-used-for-drinking-water-supply
#19
Carolina Aristizabal-Ciro, Ana María Botero-Coy, Francisco J López, Gustavo A Peñuela
In this work, the presence of selected emerging contaminants has been investigated in two reservoirs, La Fe (LF) and Rio Grande (RG), which supply water to two drinking water treatment plants (DWTPs) of Medellin, one of the most populated cities of Colombia. An analytical method based on solid-phase extraction (SPE) of the sample followed by measurement by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was developed and validated for this purpose. Five monitoring campaigns were performed in each reservoir, collecting samples from 7 sites (LF) and 10 sites (RG) at 3 different depths of the water column...
January 20, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28104718/boncat-enables-time-resolved-analysis-of-protein-synthesis-in-native-plant-tissue
#20
Weslee Glenn, Shannon E Stone, Samuel H Ho, Michael J Sweredoski, Annie Moradian, Sonja Hess, Julia Bailey-Serres, David A Tirrell
Proteomic plasticity undergirds stress responses in plants, and understanding such responses requires accurate measurement of the extent to which proteins levels are adjusted to counter external stimuli. Here, we adapt bioorthogonal non-canonical amino acid tagging (BONCAT) to interrogate protein synthesis in vegetative Arabidopsis thaliana seedlings. BONCAT relies on the translational incorporation of a non-canonical amino acid (ncAA) probe into cellular proteins. In this study, the probe is the methionine surrogate azidohomoalanine (Aha), which carries a reactive azide moiety in its amino acid side chain...
January 19, 2017: Plant Physiology
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