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https://www.readbyqxmd.com/read/28214603/the-impact-of-reduced-gastric-acid-secretion-on-dissolution-of-salts-of-weak-bases-in-the-fasted-upper-gastrointestinal-lumen-data-in-biorelevant-media-and-in-human-aspirates
#1
Chara Litou, Maria Vertzoni, Wei Xu, Filippos Kesisoglou, Christos Reppas
PURPOSE: To propose media for simulating the intragastric environment under reduced gastric acid secretion in the fasted state at three levels of simulation of the gastric environment and evaluate their usefulness in evaluating the intragastric dissolution of salts of weak bases. To evaluate the importance of bicarbonate buffer in biorelevant in vitro dissolution testing when using Level II biorelevant media simulating the environment in the fasted upper small intestine, regardless of gastric acid secretions...
February 15, 2017: European Journal of Pharmaceutics and Biopharmaceutics
https://www.readbyqxmd.com/read/28213251/on-line-monitoring-of-in-vitro-oral-bioaccessibility-tests-as-front-end-to-liquid-chromatography-for-determination-of-chlorogenic-acid-isomers-in-dietary-supplements
#2
Daniel Kremr, David J Cocovi-Solberg, Petra Bajerová, Karel Ventura, Manuel Miró
A novel fully automated in-vitro oral dissolution test assay as a front-end to liquid chromatography has been developed and validated for on-line chemical profiling and monitoring of temporal release profiles of three caffeoylquinic acid (CQA) isomers, namely, 3-CQA,4-CQA and 5-CQA, known as chlorogenic acids, in dietary supplements. Tangential-flow filtration is harnessed as a sample processing approach for on-line handling of CQA containing extracts of hard gelatin capsules and introduction of protein-free samples into the liquid chromatograph...
May 1, 2017: Talanta
https://www.readbyqxmd.com/read/28208280/an-integrated-approach-to-unique-nmr-assignment-of-methionine-methyl-resonances-in-proteins
#3
Fei Yu, Jing Qiao, John Robblee, Desiree Tsao, James Anderson, Ishan Capila
The application of methyl nuclear magnetic resonance (NMR) spectroscopy in protein side-chain structural studies offers unique advantages of greater peak sensitivity, even for high-molecular-weight proteins. Traditionally, the utility of methyl NMR has often been limited by the difficulty in assigning the methyl resonances. Herein, a mass spectrometry (MS)-assisted strategy to assign the methyl resonances of methionine residues is presented. The strategy involves partially oxidizing the methionine and quantifying the oxidation level by both NMR and liquid chromatography-mass spectrometry (LC-MS)...
February 7, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28208252/high-confidence-qualitative-identification-of-organophosphorus-nerve-agent-adducts-to-human-butyrylcholinesterase
#4
Thomas P Mathews, Melissa D Carter, Darryl Johnson, Samantha L Isenberg, Leigh Ann Graham, Jerry D Thomas, Rudolph C Johnson
In this study, a data-dependent, high-resolution tandem mass spectrometry (ddHRMS/MS) method capable of detecting all organophosphorus nerve agent (OPNA) adducts to human butyrylcholinesterase (BChE) was developed. After an exposure event, immunoprecipitation from blood with a BChE-specific antibody and digestion with pepsin produces a nine amino acid peptide containing the OPNA adduct. Signature product ions of this peptic BChE nonapeptide (FGES*AGAAS) offer a route to broadly screen for OPNA exposure. Taking this approach on an HRMS instrument identifies biomarkers, including unknowns, with high mass accuracy...
February 7, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28207780/analyzing-pepsin-degradation-assay-conditions-used-for-allergenicity-assessments-to-ensure-that-pepsin-susceptible-and-pepsin-resistant-dietary-proteins-are-distinguishable
#5
Rong Wang, Thomas C Edrington, S Bradley Storrs, Kathleen S Crowley, Jason M Ward, Thomas C Lee, Zi L Liu, Bin Li, Kevin C Glenn
The susceptibility of a dietary protein to proteolytic degradation by digestive enzymes, such as gastric pepsin, provides information on the likelihood of systemic exposure to a structurally intact and biologically active macromolecule, thus informing on the safety of proteins for human and animal consumption. Therefore, the purpose of standardized in vitro degradation studies that are performed during protein safety assessments is to distinguish whether proteins of interest are susceptible or resistant to pepsin degradation via a study design that enables study-to-study comparison...
2017: PloS One
https://www.readbyqxmd.com/read/28193043/removal-of-n-linked-glycosylations-at-acidic-ph-by-pngase-a-facilitates-hydrogen-deuterium-exchange-mass-spectrometry-analysis-of-n-linked-glycoproteins
#6
Pernille Foged Jensen, Gerard Comamala, Morten Beck Trelle, Jeppe Buur Madsen, Thomas J D Jørgensen, Kasper D Rand
Protein glycosylation is the most frequent post-translational modification and is present on more than 50% of eukaryotic proteins. Glycosylation covers a wide subset of modifications involving many types of complex oligosaccharide structures, making structural analysis of glycoproteins and their glycans challenging for most analytical techniques. Hydrogen/deuterium exchange monitored by mass spectrometry is a sensitive technique for investigation of protein conformational dynamics of complex heterogeneous proteins in solution...
December 20, 2016: Analytical Chemistry
https://www.readbyqxmd.com/read/28186144/engineering-the-residual-side-chains-of-hap-phytases-to-improve-their-pepsin-resistance-and-catalytic-efficiency
#7
Canfang Niu, Peilong Yang, Huiying Luo, Huoqing Huang, Yaru Wang, Bin Yao
Strong resistance to proteolytic attack is important for feed enzymes. Here, we selected three predicted pepsin cleavage sites, L99, L162, and E230 (numbering from the initiator M of premature proteins), in pepsin-sensitive HAP phytases YkAPPA from Yersinia kristensenii and YeAPPA from Y. enterocolitica, which corresponded to L99, V162, and D230 in pepsin-resistant YrAPPA from Y. rohdei. We constructed mutants with different side chain structures at these sites using site-directed mutagenesis and produced all enzymes in Escherichia coli for catalytic and biochemical characterization...
February 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28176198/constituents-of-leaves-from-bauhinia-curvula-benth-exert-gastroprotective-activity-in-rodents-role-of-quercitrin-and-kaempferol
#8
Ana Paula Beber, Priscila de Souza, Thaise Boeing, Lincon Bordignon Somensi, Luísa Nathália Bolda Mariano, Benhur Judah Cury, Ligia Moura Burci, Cristiane Bezerra da Silva, Euclésio Simionatto, Sérgio Faloni de Andrade, Luísa Mota da Silva
The Bauhinia genus is known as "Pata-de-Vaca" and a wide variety of these species are used in Brazilian folk medicine due to their gastroprotective properties. This study aimed to investigate the antiulcer efficacy of the hydroalcoholic extract from B. curvula (HEBC) leaves, as well as its semi-purified fraction (SPFr) and the contribution of their phytochemicals constituents for this effect. For that, ethanol 60%/HCl 0.3 M- and indomethacin-induced gastric ulcer were performed in rodents. Gastric ulcerated tissues were processed for histological, histochemical and biochemical analysis...
February 7, 2017: Inflammopharmacology
https://www.readbyqxmd.com/read/28174080/extraction-and-characterization-of-gelatin-from-the-feet-of-pekin-duck-anas-platyrhynchos-domestica-as-affected-by-acid-alkaline-and-enzyme-pretreatment
#9
Ahmadreza Abedinia, Fazilah Ariffin, Nurul Huda, Abdorreza Mohammadi Nafchi
The effects of different pretreatments on yield and composition of extraction, physicochemical, and rheological properties of duck feet gelatin (DFG) were investigated. Gelatins were extracted from the whole feet of Pekin duck with an average yield of 4.09%, 3.65%, and 5.75% for acidic (Ac-DFG), alkaline (Al-DFG), and enzymatic (En-DFG) pretreatment on a wet weight basis, respectively. Proteins at 81.38%, 79.41%, 82.55%, and 87.38% were the major composition for Ac-DFG, Al-DFG, En-DFG, and bovine, respectively...
February 4, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28169560/bovine-lactoferrin-and-lactoferricin-exert-antitumor-activities-on-human-colorectal-cancer-cells-ht-29-by-activating-various-signaling-pathways
#10
Rulan Jiang, Bo Lönnerdal
Lactoferrin (Lf) is an iron-binding glycoprotein that is present at high concentrations in milk. Bovine lactoferricin (LfcinB) is a peptide fragment generated by pepsin proteolysis of bovine lactoferrin (bLf). LfcinB consists of amino acid residues 17-41 proximal to the N-terminus of bLf and a disulfide bond between residues 19 and 36, forming a loop. Both bLf and LfcinB have been demonstrated to have antitumor activities. Colorectal cancer is the second most common cause of cancer death in developed countries...
February 2017: Biochemistry and Cell Biology, Biochimie et Biologie Cellulaire
https://www.readbyqxmd.com/read/28167392/perivascular-extracellular-matrix-hydrogels-mimic-native-matrix-microarchitecture-and-promote-angiogenesis-via-basic-fibroblast-growth-factor
#11
George R Fercana, Saigopalakrishna Yerneni, Marie Billaud, Jennifer C Hill, Paul VanRyzin, Tara D Richards, Brian M Sicari, Scott A Johnson, Stephen F Badylak, Phil G Campbell, Thomas G Gleason, Julie A Phillippi
Extracellular matrix (ECM)-derived bioscaffolds have been shown to elicit tissue repair through retention of bioactive signals. Given that the adventitia of large blood vessels is a richly vascularized microenvironment, we hypothesized that perivascular ECM contains bioactive signals that influence cells of blood vessel lineages. ECM bioscaffolds were derived from decellularized human and porcine aortic adventitia (hAdv and pAdv, respectively) and then shown have minimal DNA content and retain elastin and collagen proteins...
April 2017: Biomaterials
https://www.readbyqxmd.com/read/28117788/tunable-hydrogels-from-pulmonary-extracellular-matrix-for-3d-cell-culture
#12
Patrick A Link, Robert A Pouliot, Nabil S Mikhaiel, Bethany M Young, Rebecca L Heise
Here we present a method for establishing multiple component cell culture hydrogels for in vitro lung cell culture. Beginning with healthy en bloc lung tissue from porcine, rat, or mouse, the tissue is perfused and submerged in subsequent chemical detergents to remove the cellular debris. Histological comparison of the tissue before and after processing confirms removal of over 95% of double stranded DNA and alpha galactosidase staining suggests the majority of cellular debris is removed. After decellularization, the tissue is lyophilized and then cryomilled into a powder...
January 17, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28117122/carboxylated-single-walled-carbon-nanotube-functionalized-chiral-polymer-monoliths-for-affinity-capillary-electrochromatography
#13
Chunyue Miao, Ruihan Bai, Shujuan Xu, Tingting Hong, Yibing Ji
Carboxylated single-walled carbon nanotubes (c-SWNTs) were incorporated into poly(glycidylmethacrylate-co-ethylene glycol dimethacrylate) [poly(GMA-co-EDMA)] monoliths to develop a novel monolithic stationary phase for capillary electrochromatography. The prepared monoliths were characterized by scanning electron microscopy and nitrogen adsorption. Additionally, pepsin, which is a chiral selector, was bonded to the c-SWNT-incorporated monoliths via epoxide groups as reactive sites and glutaraldehyde as the spacer...
March 3, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28115770/effects-of-heat-and-ph-treatments-and-in-vitro-digestion-on-the-biological-activity-of-protein-hydrolysates-of-amaranthus-hypochondriacus-l-grain
#14
J López-Sánchez, E Ponce-Alquicira, R Pedroza-Islas, A de la Peña-Díaz, J Soriano-Santos
The aim of this work was to assess the effects of temperature (T), time (t) and pH treatments and an in vitro digestion on the stability of the angiotensin I-converting-enzyme-inhibitory activity (ACEIA) and antithrombotic activity (ATA; assessed as inhibition of platelet aggregation) of selected protein hydrolysates of amaranth named Alb1H103 and GloH88 and GluH24 with dipeptidyl peptidase IV inhibitory activity (DPPIVIA). Heat treatment (40-100 °C) for 1 h showed no significant differences among ACEIA, DPPIVIA and ATA of the heated hydrolysates at pH 4 and 7...
December 2016: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/28114854/gastrointestinal-stability-of-dihydromyricetin-myricetin-and-myricitrin-an-in-vitro-investigation
#15
Dong Xiang, Chen-Guang Wang, Wen-Qing Wang, Chun-Yang Shi, Wei Xiong, Meng-Die Wang, Jian-Guo Fang
The gastrointestinal (GI) stability of three flavonoids, dihydromyricetin (DMY), myricetin (MYR), and myricitrin (MYT), was examined in simulated physiological fluids. Several factors that may influence the degradation rate of theses flavonoids were evaluated, including pH and the presence of pepsin and pancreatin enzymes. We found that GI stability followed the order of MYT > DMY > MYR. These flavonoids were stable in simulated gastric fluids and buffer solutions (pH 1.2), but encountered a pseudo-first-order kinetic degradation in simulated intestinal fluids and buffer solutions (pH 6...
January 23, 2017: International Journal of Food Sciences and Nutrition
https://www.readbyqxmd.com/read/28113517/the-intrinsic-pepsin-resistance-of-interleukin-8-can-be-explained-from-a-combined-bioinformatical-and-experimental-approach
#16
Gerd Anders, Ulrich Hassiepen, Stephan Theisgen, Stephan Heymann, Lionel Muller, Tania Panigada, Daniel Huster, Sergey A Samsonov
Interleukin-8 (IL-8, CXCL8) is a neutrophil chemotactic factor belonging to the family of chemokines. IL-8 was shown to resist pepsin cleavage displaying its high resistance to this protease. However, the molecular mechanisms underlying this resistance are not fully understood. Using our in-house database containing the data on three-dimensional arrangements of secondary structure elements from the whole Protein Data Bank, we found a striking structural similarity between IL-8 and pepsin inhibitor-3. Such similarity could play a key role in understanding IL-8 resistance to the protease pepsin...
October 3, 2016: IEEE/ACM Transactions on Computational Biology and Bioinformatics
https://www.readbyqxmd.com/read/28103393/the-correlation-between-in-vitro-antioxidant-activity-and-immunomodulatory-activity-of-enzymatic-hydrolysates-from-selenium-enriched-rice-protein
#17
Yong Fang, Xi Chen, Peizhu Luo, Fei Pei, Benard Muinde Kimatu, Kunlun Liu, Mengjia Du, Weifen Qiu, Qiuhui Hu
The antioxidant and immunomodulatory activities of selenium-enriched rice protein hydrolysates (Se-PH) were evaluated by a cellular antioxidant activity test and macrophage proliferation and phagocytosis assays, respectively. The results showed that trypsin hydrolysate provided the highest proliferation rate of 60.91% at a concentration of 100 μg/mL. Moreover, a remarkable rise in the phagocytosis rates for trypsin hydrolysate (64.1%) and pepsin-trypsin hydrolysate (54.5%) was observed when the sample concentrations were increased to 50 μg/mL...
January 19, 2017: Journal of Food Science
https://www.readbyqxmd.com/read/28103327/isolation-characterization-and-evaluation-of-collagen-from-jellyfish-rhopilema-esculentum-kishinouye-for-use-in-hemostatic-applications
#18
Xiaochen Cheng, Ziyu Shao, Chengbo Li, Lejun Yu, Mazhar Ali Raja, Chenguang Liu
Hemostat has been a crucial focus since human body is unable to control massive blood loss, and collagen proves to be an effective hemostat in previous studies. In this study, collagen was isolated from the mesoglea of jellyfish Rhopilema esculentum Kishinouye and its hemostatic property was studied. The yields of acid-soluble collagen (ASC) and pepsin-soluble (PSC) were 0.12% and 0.28% respectively. The SDS-PAGE patterns indicated that the collagen extracted from jellyfish mesoglea was type I collagen. The lyophilized jellyfish collagen sponges were cross-linked with EDC and interconnected networks in the sponges were revealed by scanning electron microscope (SEM)...
2017: PloS One
https://www.readbyqxmd.com/read/28098801/a-novel-antihypertensive-derived-from-adlay-coix-larchryma-jobi-l-var-ma-yuen-stapf-glutelin
#19
Bin Li, Liansheng Qiao, Lingling Li, Yanling Zhang, Kai Li, Lingzhi Wang, Yanjiang Qiao
Our previous studies have shown that Coix glutelin pepsin hydrolysate can effectively inhibit angiotensin converting enzyme (ACE) activity in vitro. The main purpose of this study was to obtain potent anti-hypertensive peptides from Coix glutelin. The Coix glutelin hydrolysates (CGH) were prepared by pepsin catalysis and further separated by an ultrafitration (UF) system, gel filtration chromatography (GFC) and reversed-phase high performance liquid chromatography (RP-HPLC). As a result, the sub-fraction F5-3 had the highest ACE-inhibitory activity...
January 13, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28091678/pepsin-egg-white-hydrolysate-modulates-gut-microbiota-in-zucker-obese-rats
#20
Teresa Requena, Marta Miguel, Marta Garcés-Rimón, M Carmen Martínez-Cuesta, Rosina López-Fandiño, Carmen Peláez
There is limited information that relates the intake of food-derived bioactive peptides and the gut microbiota. We have previously described a pepsin hydrolysate of egg white (EWH) that ameliorates fat accumulation and dyslipidemia, while reducing oxidative stress and inflammation markers in obese Zucker rats. The aim of this study was to associate the beneficial effects of EWH with gut microbiota changes in these animals. Obese Zucker rats received daily 750 mg kg(-1) EWH in drinking water for 12 weeks and faeces were analysed for microbial composition and metabolic compounds in comparison with Zucker lean rats and obese controls...
January 16, 2017: Food & Function
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