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https://www.readbyqxmd.com/read/28445813/microfluidic-integrated-patterned-ito-immunosensor-for-rapid-detection-of-prostate-specific-membrane-antigen-biomarker-in-prostate-cancer
#1
Rajesh Seenivasan, Chandra K Singh, Jay W Warrick, Nihal Ahmad, Sundaram Gunasekaran
An optically transparent patterned indium tin oxide (ITO) three-electrode sensor integrated with a microfluidic channel was designed for label-free immunosensing of prostate-specific membrane antigen (PSMA), a prostate cancer (PCa) biomarker, expressed on prostate tissue and circulating tumor cells but also found in serum. The sensor relies on cysteamine capped gold nanoparticles (N-AuNPs) covalently linked with anti-PSMA antibody (Ab) for target specificity. A polydimethylsiloxane (PDMS) microfluidic channel is used to efficiently and reproducibly introduce sample containing soluble proteins/cells to the sensor...
April 11, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28434875/covalent-protein-labeling-at-glutamic-acids
#2
Pablo Martín-Gago, Eyad K Fansa, Michael Winzker, Sandip Murarka, Petra Janning, Carsten Schultz-Fademrecht, Matthias Baumann, Alfred Wittinghofer, Herbert Waldmann
Covalent labeling of amino acids in proteins by reactive small molecules, in particular at cysteine SH and lysine NH groups, is a powerful approach to identify and characterize proteins and their functions. However, for the less-reactive carboxylic acids present in Asp and Glu, hardly any methodology is available. Employing the lipoprotein binding chaperone PDE6δ as an example, we demonstrate that incorporation of isoxazolium salts that resemble the structure and reactivity of Woodward's reagent K into protein ligands provides a novel method for selective covalent targeting of binding site carboxylic acids in whole proteomes...
April 13, 2017: Cell Chemical Biology
https://www.readbyqxmd.com/read/28430191/activating-lattice-oxygen-redox-reactions-in-metal-oxides-to-catalyse-oxygen-evolution
#3
Alexis Grimaud, Oscar Diaz-Morales, Binghong Han, Wesley T Hong, Yueh-Lin Lee, Livia Giordano, Kelsey A Stoerzinger, Marc T M Koper, Yang Shao-Horn
Understanding how materials that catalyse the oxygen evolution reaction (OER) function is essential for the development of efficient energy-storage technologies. The traditional understanding of the OER mechanism on metal oxides involves four concerted proton-electron transfer steps on metal-ion centres at their surface and product oxygen molecules derived from water. Here, using in situ (18)O isotope labelling mass spectrometry, we provide direct experimental evidence that the O2 generated during the OER on some highly active oxides can come from lattice oxygen...
May 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28429595/ultrasensitive-detection-of-micrornas-with-morpholino-functionalized-nanochannel-biosensor
#4
Tangbin Liao, Xiaorui Li, Qian Tong, Kai Zou, Hang Zhang, Lina Tang, Zhongyue Sun, Guo-Jun Zhang
Here we demonstrate a phosphorodiamidate morpholino oligos (PMO)-functionlized nanochannel biosensor for label-free detection of microRNAs (miRNAs) with ultrasensitivity and high sequence-specificity. PMO, as a capture probe, was covalently anchored on the nanochannel surface. Because of the neutral character and high sequence-specific affinity of PMO, hybridization efficiency between PMO and miRNAs was enhanced, thus decreasing background signals largely and improving the detection specificity and sensitivity highly...
April 21, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28420127/glycosaminoglycan-binding-and-non-endocytic-membrane-translocation-of-cell-permeable-octaarginine-monitored-by-real-time-in-cell-nmr-spectroscopy
#5
Yuki Takechi-Haraya, Kenzo Aki, Yumi Tohyama, Yuichi Harano, Toru Kawakami, Hiroyuki Saito, Emiko Okamura
Glycosaminoglycans (GAGs), which are covalently-linked membrane proteins at the cell surface have recently been suggested to involve in not only endocytic cellular uptake but also non-endocytic direct cell membrane translocation of arginine-rich cell-penetrating peptides (CPPs). However, in-situ comprehensive observation and the quantitative analysis of the direct membrane translocation processes are challenging, and the mechanism therefore remains still unresolved. In this work, real-time in-cell NMR spectroscopy was applied to investigate the direct membrane translocation of octaarginine (R8) into living cells...
April 15, 2017: Pharmaceuticals
https://www.readbyqxmd.com/read/28417900/green-approach-to-photoluminescent-carbon-dots-for-imaging-of-gram-negative-bacteria-escherichia-coli
#6
Poushali Das, Madhuparna Bose, Sayan Ganguly, Subhadip Mondal, Amit Kumar Das, Susanta Banerjee, Narayan Chandra Das
Fluorescent carbon dots, zero-dimensional nanomaterials with surface ligands, have been studied extensively over the past few years in biolabelling or fluorescence-based live cell assays. In the past, synthetic organic dyes have been used as cell tracking materials, but they have severe limitations; fluorescent carbon dots may pave the way to biolabelling and cell imaging. In this work, green fluorescent carbon dots have been synthesized from a green source, gram, without any sort of covalent or ionic modifications...
May 12, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28412273/efficient-inhibition-of-influenza-a-viral-replication-in-cells-by-deoxyribozymes-delivered-by-nanocomposites
#7
Marina Repkova, Asya Levina, Boris Chelobanov, Zinfer Ismagilov, Natalia Shatskaya, Sergei Baiborodin, Ekaterina Filippova, Natalia Mazurkova, Valentina Zarytova
Nucleic-acid-based drugs are a promising class of novel therapeutics; however, their use in medicine is widely limited because of insufficient delivery into cells. This article proposes a new delivery strategy of nucleic acid fragments into cells as components of TiO2-based nanocomposites. For the first time, unmodified Dz molecules were non-covalently immobilized on TiO2 nanoparticles precovered with polylysine (TiO2•PL) with the formation of (TiO2•PL)•Dz nanocomposites. DNAzymes in the proposed nanocomposites were shown to retain their ability to cleave the RNA target in a cell-free system with the same selectivity as unbound Dz molecules...
April 12, 2017: International Journal of Antimicrobial Agents
https://www.readbyqxmd.com/read/28411807/a-sensitive-and-disposable-indium-tin-oxide-based-electrochemical-immunosensor-for-label-free-detection-of-mage-1
#8
Burçak Demirbakan, Mustafa Kemal Sezgintürk
MAGE-1 (MAGE, for melanoma antigen), was identified by virtue of its processing and cell surface expression as a tumor-specific peptide bound to major histocompatibility complexes which was reactive with autolytic T cells. 3-Glycidoxypropyltrimethoxysilane (3-GOPS) is frequently employed for the preparation of dense heterometal hybrid polymers which are used, e.g., for hard coatings of organic polymers and contact lens materials in the optical industry. In this study, we have improved a new immunological biosensor with indium tin oxide (ITO)...
July 1, 2017: Talanta
https://www.readbyqxmd.com/read/28411182/pegylation-rate-influences-peptide-based-nanoparticles-mediated-sirna-delivery-in-vitro-and-in-vivo
#9
Gudrun Aldrian, Anaïs Vaissière, Karidia Konate, Quentin Seisel, Eric Vivès, Frédéric Fernandez, Véronique Viguier, Coralie Genevois, Franck Couillaud, Héléne Démèné, Dina Aggad, Aurélie Covinhes, Stéphanie Barrère-Lemaire, Sébastien Deshayes, Prisca Boisguerin
Small interfering RNAs (siRNAs) present a strong therapeutic potential because of their ability to inhibit the expression of any desired protein. Recently, we developed the retro-inverso amphipathic RICK peptide as novel non-covalent siRNA carrier. This peptide is able to form nanoparticles (NPs) by self-assembling with the siRNA resulting in the fully siRNA protection based on its protease resistant peptide sequence. With regard to an in vivo application, we investigated here the influence of the polyethylene glycol (PEG) grafting to RICK NPs on their in vitro and in vivo siRNA delivery properties...
April 11, 2017: Journal of Controlled Release: Official Journal of the Controlled Release Society
https://www.readbyqxmd.com/read/28406238/new-method-for-quantification-of-gasotransmitter-hydrogen-sulfide-in-biological-matrices-by-lc-ms-ms
#10
Bo Tan, Sheng Jin, Jiping Sun, Zhongkai Gu, Xiaotian Sun, Yichun Zhu, Keke Huo, Zonglian Cao, Ping Yang, Xiaoming Xin, Xinhua Liu, Lilong Pan, Furong Qiu, Jian Jiang, Yiqun Jia, Fuyuan Ye, Ying Xie, Yi Zhun Zhu
Hydrogen sulfide exists widely in mammalian tissues and plays a vital role in physiological and pathophysiological processes. However, striking differences with orders of magnitude were observed for the detected hydrogen sulfide concentrations in biological matrices among different measurements in literature, which lead to the uncertainty for examination the biological relevance of hydrogen sulfide. Here, we developed and validated a liquid chromatography- mass spectrometry (LC-MS/MS) method for the determination of hydrogen sulfide in various biological matrices by determination of a derivative of hydrogen sulfide and monobromobimane named sulfide dibimane (SDB)...
April 13, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28403743/nonclinical-profile-of-blz-100-a-tumor-targeting-fluorescent-imaging-agent
#11
Julia Parrish-Novak, Kelly Byrnes-Blake, Narine Lalayeva, Stefanie Burleson, Janean Fidel, Rhonda Gilmore, Pamela Gayheart-Walsten, Gregory A Bricker, William J Crumb, K S Tarlo, Stacey Hansen, Valorie Wiss, Errol Malta, William S Dernell, James M Olson, Dennis M Miller
BLZ-100 is a single intravenous use, fluorescent imaging agent that labels tumor tissue to enable more complete and precise surgical resection. It is composed of a chlorotoxin peptide covalently bound to the near-infrared fluorophore indocyanine green. BLZ-100 is in clinical development for intraoperative visualization of human tumors. The nonclinical safety and pharmacokinetic (PK) profile of BLZ-100 was evaluated in mice, rats, canines, and nonhuman primates (NHP). Single bolus intravenous administration of BLZ-100 was well tolerated, and no adverse changes were observed in cardiovascular safety pharmacology, PK, and toxicology studies in rats and NHP...
March 2017: International Journal of Toxicology
https://www.readbyqxmd.com/read/28403559/integrin-receptor-targeting-rgdk-tagged-nanocarrier-anticancer-efficacy-of-loaded-curcumin
#12
Prasanta Kumar Das, Krishnendu Das, Sahithi Nimushakavi, Arabinda Chaudhuri
Herein we report the design and development of α5β1 integrin receptor specific RGDK-lipopeptide associated non-covalently dispersed single walled carbon nanotube (SWNT) that selectively deliver anti-cancer curcumin to tumor cells. Arg-Gly-Asp-Lys (RGDK) tetrapeptide tagged amphiphiles were synthesized that efficiently dispersed SWNT with >80% suspension stability index in cell culture media. MTT & LDH based cell viability assays in tumor (melanoma, B16F10) and non-cancerous (mouse fibroblast cells, NIH3T3) revealed non-cytotoxic nature of RGDK-lipopeptide-SWNT conjugates...
April 12, 2017: ChemMedChem
https://www.readbyqxmd.com/read/28401975/imidazolium-labeled-glycosides-as-probes-to-harness-glycosyltransferase-activity-in-human-breast-milk
#13
I Sittel, M C Galan
Imidazolium-labeled (ITag-) glycosides are used to harness the glycosyltransferase activity directly from human breast milk. The covalently attached ionic labels provide a bifunctional chemical handle that is used to monitor reaction progress by MS, as well as aid in product purification from complex mixtures. The technology is exemplified in the synthesis of biologically relevant oligosaccharide analogs, LacNAc-ITag, ITag-Lewis(x) and ITag-Lewis(a), in a matter of days from human breast milk without having to isolate specific enzymes...
April 12, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28397923/signal-transduction-in-oligoamide-foldamers-by-selective-non-covalent-binding-of-chiral-phosphates-at-a-urea-binding-site
#14
Katharina Gratzer, Vincent Diemer, Jonathan Clayden
The transduction of biological signals depends on the spatial communication of conformational change. We report a synthetic mimic of this signal transduction process in which non-covalent binding induces a change in the position of equilibrium between two rapidly interconverting screw-sense conformers of a synthetic helical polyamide. Selectivity was achieved by incorporating at the N-terminus of the polyamide a urea-based anion recognition site capable of binding chiral phosphate anions. As a result of solvent-dependent binding, an induced conformational change propagates from the binding site through the amide chain, leading to a screw-sense preference detectable in the form of a chemical shift separation between two NMR active (13)C labels...
April 11, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28396447/dual-optical-control-and-mechanistic-insights-into-photoswitchable-group-ii-and-iii-metabotropic-glutamate-receptors
#15
Joshua Levitz, Johannes Broichhagen, Philipp Leippe, David Konrad, Dirk Trauner, Ehud Y Isacoff
G protein-coupled receptor (GPCR) signaling occurs in complex spatiotemporal patterns that are difficult to probe using standard pharmacological and genetic approaches. A powerful approach for dissecting GPCRs is to use light-controlled pharmacological agents that are tethered covalently and specifically to genetically engineered receptors. However, deficits in our understanding of the mechanism of such photoswitches have limited application of this approach and its extension to other GPCRs. In this study, we have harnessed the power of bioorthogonal tethering to SNAP and CLIP protein tags to create a family of light-gated metabotropic glutamate receptors (mGluRs)...
April 10, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28387482/proximity-dependent-labeling-methods-for-proteomic-profiling-in-living-cells
#16
REVIEW
Chiao-Lin Chen, Norbert Perrimon
Characterizing the proteome composition of organelles and subcellular regions of living cells can facilitate the understanding of cellular organization as well as protein interactome networks. Proximity labeling-based methods coupled with mass spectrometry (MS) offer a high-throughput approach for systematic analysis of spatially restricted proteomes. Proximity labeling utilizes enzymes that generate reactive radicals to covalently tag neighboring proteins with biotin. The biotinylated endogenous proteins can then be isolated for further analysis by MS...
April 7, 2017: Wiley Interdisciplinary Reviews. Developmental Biology
https://www.readbyqxmd.com/read/28387473/combining-affinity-enrichment-cross-linking-with-photo-amino-acids-and-mass-spectrometry-for-probing-protein-kinase-d2-interactions
#17
Björn Häupl, Christian H Ihling, Andrea Sinz
We present a novel approach that relies on the affinity capture of protein interaction partners from a complex mixture, followed by covalent fixation via UV-induced activation of incorporated diazirine photo-reactive amino acids (photo-methionine and photo-leucine). The captured protein complexes are enzymatically digested and interacting proteins are identified and quantified by label-free LC/MS analysis. Using HeLa cell lysates with photo-methionine and photo-leucine-labeled proteins, we were able to capture and preserve protein interactions that are otherwise elusive in conventional pull-down experiments...
April 7, 2017: Proteomics
https://www.readbyqxmd.com/read/28387242/chemical-labelling-for-visualizing-native-ampa-receptors-in-live-neurons
#18
Sho Wakayama, Shigeki Kiyonaka, Itaru Arai, Wataru Kakegawa, Shinji Matsuda, Keiji Ibata, Yuri L Nemoto, Akihiro Kusumi, Michisuke Yuzaki, Itaru Hamachi
The location and number of neurotransmitter receptors are dynamically regulated at postsynaptic sites. However, currently available methods for visualizing receptor trafficking require the introduction of genetically engineered receptors into neurons, which can disrupt the normal functioning and processing of the original receptor. Here we report a powerful method for visualizing native α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptors (AMPARs) which are essential for cognitive functions without any genetic manipulation...
April 7, 2017: Nature Communications
https://www.readbyqxmd.com/read/28382184/investigation-of-the-action-of-poly-adp-ribose-synthesising-enzymes-on-nad-analogues
#19
Sarah Wallrodt, Edward L Simpson, Andreas Marx
ADP-ribosyl transferases with diphtheria toxin homology (ARTDs) catalyse the covalent addition of ADP-ribose onto different acceptors forming mono- or poly(ADP-ribos)ylated proteins. Out of the 18 members identified, only four are known to synthesise the complex poly(ADP-ribose) biopolymer. The investigation of this posttranslational modification is important due to its involvement in cancer and other diseases. Lately, metabolic labelling approaches comprising different reporter-modified NAD(+) building blocks have stimulated and enriched proteomic studies and imaging applications of ADP-ribosylation processes...
2017: Beilstein Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28379685/specific-recognition-of-human-influenza-virus-with-pedot-bearing-sialic-acid-terminated-trisaccharides
#20
Wenfeng Hai, Tatsuro Goda, Hiroaki Takeuchi, Shoji Yamaoka, Yukichi Horiguchi, Akira Matsumoto, Yuji Miyahara
Conducting polymers are good candidates for biosensor applications when molecular recognition element is imparted. We developed trisaccharide-grafted conducting polymers for label-free detection of the human influenza A virus (H1N1) with high sensitivity and specificity. A 3,4-ethylenedioxythiophene (EDOT) derivative bearing an oxylamine moiety was electrochemically copolymerized with EDOT. The obtained film was characterized by cyclic voltammetry, X-ray photoelectron spectroscopy, scanning electron microscopy, stylus surface profilometer, and AC-impedance spectroscopy...
April 13, 2017: ACS Applied Materials & Interfaces
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