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https://www.readbyqxmd.com/read/29149638/roles-of-n-and-c-terminal-domains-in-the-ligand-binding-properties-of-cytoglobin
#1
Shumpei Hanai, Hirofumi Tsujino, Taku Yamashita, Ryo Torii, Hitomi Sawai, Yoshitsugu Shiro, Koji Oohora, Takashi Hayashi, Tadayuki Uno
Cytoglobin (Cygb) is a member of the hexacoordinated globin protein family and is expressed ubiquitously in rat and human tissues. Although Cygb is reportedly upregulated under hypoxic conditions both in vivo and in vitro, suggesting a physiological function to protect cells under hypoxic/ischemic conditions by scavenging reactive oxygen species or by signal transduction, the mechanisms associated with this function have not been fully elucidated. Recent studies comparing Cygbs among several species suggest that mammalian Cygbs show a distinctly longer C-terminal domain potentially involved in unique physiological functions...
November 9, 2017: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/29149466/microsecond-timescale-protein-dynamics-a-combined-solid-state-nmr-approach
#2
Petra Rovó, Rasmus Linser
Conformational exchange in proteins is a major determinant in protein functionality. In particular, the μs-ms timescale is associated with enzymatic activity and interactions between biological molecules. We show here that a comprehensive data set of R1ρ relaxation dispersion profiles employing multiple effective fields and tilt angles can be easily obtained in perdeuterated, partly back-exchanged proteins at fast magic-angle spinning and further complemented with chemical-exchange saturation transfer NMR experiments...
November 17, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/29149068/a-new-uplc-ms-ms-method-for-the-characterization-and-discrimination-of-polysaccharides-from-genus-ephedra-based-on-enzymatic-digestions
#3
Yong-Gang Xia, Tian-Long Wang, Li-Ming Sun, Jun Liang, Bing-You Yang, Hai-Xue Kuang
Ephedra sinica polysaccharides have been reported to possess important activities, so quality evaluation of polysaccharides from the genus Ephedra is urgent. In this study, enzymatic digestions were performed to establish multiple saccharide fingerprints by ultra-performance liquid chromatography with electrospray ionization triple quadrupole linear ion trap mass spectrometry (UPLC-ESI-TQ-MS/MS) based on a multiple-reaction monitoring in negative mode. Under optimum UPLC-ESI⁻-TQ-MS/MS conditions, excellent separation and quantification of 21 constituents were achieved within 20 min on a solid core column with a 1...
November 17, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29149057/effects-of-surfactants-on-the-preparation-of-nanocellulose-pla-composites
#4
Kirsi Immonen, Panu Lahtinen, Jaakko Pere
Thermoplastic composite materials containing wood fibers are gaining increasing interest in the manufacturing industry. One approach is to use nano- or micro-size cellulosic fibrils as additives and to improve the mechanical properties obtainable with only small fibril loadings by exploiting the high aspect ratio and surface area of nanocellulose. In this study, we used four different wood cellulose-based materials in a thermoplastic polylactide (PLA) matrix: cellulose nanofibrils produced from softwood kraft pulp (CNF) and dissolving pulp (CNFSD), enzymatically prepared high-consistency nanocellulose (HefCel) and microcellulose (MC) together with long alkyl chain dispersion-improving agents...
November 17, 2017: Bioengineering
https://www.readbyqxmd.com/read/29148804/a-nanobionic-light-emitting-plant
#5
Seon-Yeong Kwak, Juan Pablo Giraldo, Min Hao Wong, Volodymyr Koman, Tedrick Lew, Jon Ell, Mark Weidman, Rosalie Sinclair, Markita P Landry, William A Tisdale, Michael S Strano
The engineering of living plants for visible light emission and sustainable illumination is compelling because plants possess independent energy generation and storage mechanisms and autonomous self-repair. Herein, we demonstrate a plant nanobionic approach that enables exceptional luminosity and lifetime utilizing four chemically-interacting nanoparticles, including firefly luciferase conjugated silica (SNP-Luc), D-luciferin releasing poly(lactic-co-glycolic acid) (PLGA-LH2), coenzyme A functionalized chitosan (CS-CoA) and semiconductor nanocrystal phosphors for longer wavelength modulation...
November 17, 2017: Nano Letters
https://www.readbyqxmd.com/read/29148746/keto-enol-tautomerization-triggers-an-electrophilic-aldehyde-deformylation-reaction-by-a-nonheme-manganese-iii-peroxo-complex
#6
Fabián G Cantú Reinhard, Prasenjit Barman, Gourab Mukherjee, Jitendra Kumar, Deep Kumar, Devesh Kumar, Chivukula V Sastri, Sam P de Visser
Oxygen atom transfer by high-valent enzymatic intermediates remains an enigma in chemical catalysis. In particular, manganese is an important first-row metal involved in key biochemical processes including the biosynthesis of mo-lecular oxygen (through the photosystem II complex) and biodegradation of toxic superoxide to hydrogen peroxide by superoxide dismutase. Biomimetic models of these biological systems have been developed to gain understanding on the structure and properties of short-lived intermediates but also with the aim to create environmentally benign oxidants...
November 17, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/29148719/effect-of-antigen-retrieval-methods-on-non-specific-binding-of-anti-body-metal-nanoparticle-conjugates-on-ffpe-tissue
#7
Yuying Zhang, Xinping Wang, Sven Perner, Ágnes Bánkfalvi, Sebastian Schlücker
Immunohistochemical analysis of FFPE tissues provides important diagnostic and prognostic information in pathology. Metal nanoparticles (NPs) and in particular surface-enhanced Raman scattering (SERS) nanotags as a new class of labelling reagents are promising to be used for multiplexed protein profiling on tissue sections. However, non-specific binding of NPs onto the tissue specimens greatly hampers their clinical applications. In this study, we found that the antigen retrieval method strongly influences the extent of non-specific binding of the antibody-SERS NP conjugates to the tissue...
November 17, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/29148585/arsenite-downregulates-h3k4-trimethylation-and-h3k9-dimethylation-during-transformation-of-human-bronchial-epithelial-cells
#8
Wei Tu, Yin Liu, Chengfeng Xie, Xue Zhou
Arsenic is an established human carcinogen but with weak mutagenic activity. The mechanisms of arsenic-induced carcinogenesis are not well understood. In the present study, we investigated the role of histone methylation in transformation of human bronchial epithelial (BEAS-2B) cells. After 16 weeks' exposure, cells were transformed by 0.1, 0.5 and 1 μm arsenite. Global trimethylated H3K4 (H3K4me3) was decreased by 0.1 μm arsenite at 12 weeks, and 0.5 and 1 μm arsenite at 8, 12 and 16 weeks, which could be attributed to reduced histone methyltransferase activities, increased histone demethylase (HDM) activities as well as increased protein levels of H3K4 demethylase KDM5A...
November 17, 2017: Journal of Applied Toxicology: JAT
https://www.readbyqxmd.com/read/29148558/ultrasound-propelled-nanowire-motors-enhance-asparaginase-enzymatic-activity-against-cancer-cells
#9
Murat Uygun, Beatriz Jurado-Sánchez, Deniz Aktas Uygun, Virendra Vikram Singh, Liangfang Zhang, Joseph Wang
Ultrasound-(US) propelled nanowires consisting of Au/Ni/Au/PEDOT-PPy-COOH segments are modified with asparaginase enzyme and applied as an effective anti-cancer agent. After immobilization of asparaginase onto the surface of the nanowire motors, the enzyme displays enhanced thermal and pH stabilities, improved resistance towards protease, and higher affinity for the substrate. The fast motion of the motor-carrying asparaginase leads to greatly accelerated biocatalytic depletion of asparagine and hence to a significantly enhanced inhibition efficacy against El4 lymphoma cancer cells (92%) as compared to free enzyme counterpart (17%) and other control groups...
November 17, 2017: Nanoscale
https://www.readbyqxmd.com/read/29148266/nad-dependent-dehydrogenase-pctp-and-plp-dependent-aminotransferase-pctc-catalyze-the-first-post-glycosylation-modification-of-sugar-intermediate-in-pactamycin-biosynthesis
#10
Akane Hirayama, Jinmiao Chu, Ena Goto, Fumitaka Kudo, Tadashi Eguchi
The unique five-membered aminocyclitol core of the antitumor antibiotic pactamycin originates from D-glucose, so unprecedented enzymatic modifications of the sugar intermediate are involved in the biosynthesis. However, the order of the modification reactions remains elusive. Here, we examined the timing of introduction of an amino group into certain sugar-derived intermediates using recombinant enzymes that are encoded in the pactamycin biosynthesis gene cluster. We found that the NAD+-dependent alcohol dehydrogenase PctP and pyridoxal 5'-phosphate-dependent aminotransferase PctC convert N-acetyl-D-glucosaminyl-3-aminoacetophonone to 3'-amino-3'-deoxy-GlcNAc-3AAP...
November 17, 2017: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/29148251/the-enzymatic-detoxification-of-the-mycotoxin-deoxynivalenol-identification-of-depa-from-the-don-epimerization-pathway
#11
Jason Carere, Yousef I Hassan, Dion Lepp, Ting Zhou
The biological detoxification of mycotoxins, including deoxynivalenol (DON), represents a very promising approach to address the challenging problem of cereal grain contamination. The recent discovery of Devosia mutans 17-2-E-8 (Devosia spp. 17-2-E-8), a bacterial isolate capable of transforming DON to the non-toxic stereoisomer 3-epi-deoxynivalenol, along with earlier reports of bacterial species capable of oxidizing DON to 3-keto-DON, has generated interest in the possible mechanism and enzyme(s) involved...
November 17, 2017: Microbial Biotechnology
https://www.readbyqxmd.com/read/29148167/monitoring-resistance-of-cydia-pomonella-l-spanish-field-populations-to-new-chemical-insecticides-and-the-mechanisms-involved
#12
Dolors Bosch, Marcela A Rodríguez, Jesús Avilla
BACKGROUND: A widespread resistance of Cydia pomonella to organophosphates was demonstrated in populations from the Spanish Ebro Valley area that showed high levels of enzymatic detoxification. To determine the efficacy of new insecticides, neonate larvae bioassays were carried out on twenty field codling moth populations collected from three different Spanish apple production areas. Synergist bioassays were performed to detect the enzymatic mechanisms involved. RESULTS: The least active ingredients were methoxyfenozide, with 100% of the populations showing significantly lower mortality than the susceptible strain, and lambda-cyhalothrin, with very high resistant ratios (872...
November 16, 2017: Pest Management Science
https://www.readbyqxmd.com/read/29147976/evaluation-of-microbial-consortia-and-chemical-changes-in-spontaneous-maize-bran-fermentation
#13
Marilù Decimo, Mattia Quattrini, Giovanni Ricci, Maria Grazia Fortina, Milena Brasca, Tiziana Silvetti, Federica Manini, Daniela Erba, Franca Criscuoli, Maria Cristina Casiraghi
Sustainable exploitation of agro-industrial by-products has attracted great interest in cereal bran valorization. In this research, a polyphasic approach has been carried out to characterize maize bran at microbiological and chemical level during a sourdough like fermentation process, in order to enhance its technological and nutritional properties. Autochthonous microbiota was isolated at different refreshment steps and subjected to identification and molecular characterization. Fermentation was characterized by a rapid increase in lactic acid bacteria and yeasts, with a co-dominance, at the initial stage, of Weissella spp...
November 16, 2017: AMB Express
https://www.readbyqxmd.com/read/29147970/effect-of-different-salinities-on-gene-expression-and-activity-of-digestive-enzymes-in-the-thick-lipped-grey-mullet-chelon-labrosus
#14
REVIEW
I M Pujante, F J Moyano, J A Martos-Sitcha, J M Mancera, G Martínez-Rodríguez
The effects of different environmental salinities (0, 12, 40, and 55 ppt) on pepsinogen 2 (pga2), trypsinogen 2 (try2), chymotrypsinogen (ctr), and pancreatic alpha-amylase (amy2a) gene expression, and on the total activities of their corresponding enzymes, were assessed in Chelon labrosus juveniles, after their corresponding full-complementary DNA sequences were cloned. Furthermore, the quantitative effect of different salinities on the hydrolysis of feed protein by fish digestive enzymes was evaluated using an in vitro system...
November 17, 2017: Fish Physiology and Biochemistry
https://www.readbyqxmd.com/read/29147907/protein-repair-from-glycation-by-glyoxals-by-the-dj-1-family-maillard-deglycases
#15
Mouadh Mihoub, Jad Abdallah, Gilbert Richarme
DJ-1 and its prokaryotic homologs, Hsp31, YhbO and YajL from Escherichia coli and PfpI from Pyrococcus furiosus, repair proteins from glycation by glyoxals (R-CO-CHO), which constitute their major glycating agents. Glycation is a non-enzymatic covalent reaction discovered by Louis Camille Maillard in 1912, between reactive carbonyls (reducing sugars and glyoxals) and amino acids (cysteine, arginine and lysine), which inactivates proteins. By degrading Maillard adducts formed between carbonyls and thiols or amino groups, the DJ-1 family Maillard deglycases prevent the formation of the so-called advanced glycation end products (AGEs) that arise from Maillard adducts after dehydrations, oxidations and rearrangements...
2017: Advances in Experimental Medicine and Biology
https://www.readbyqxmd.com/read/29147660/analytical-validation-of-a-new-enzymatic-and-automatable-method-for-d-xylose-measurement-in-human-urine-samples
#16
Israel Sánchez-Moreno, Carmen Monsalve-Hernando, Ana Godino, Luis Illa, María Jesús Gaspar, Guillermo Manuel Muñoz, Ana Díaz, José Luis Martín, Eduardo García-Junceda, Alfonso Fernández-Mayoralas, Carmen Hermida
Hypolactasia, or intestinal lactase deficiency, affects more than half of the world population. Currently, xylose quantification in urine after gaxilose oral administration for the noninvasive diagnosis of hypolactasia is performed with the hand-operated nonautomatable phloroglucinol reaction. This work demonstrates that a new enzymatic xylose quantification method, based on the activity of xylose dehydrogenase from Caulobacter crescentus, represents an excellent alternative to the manual phloroglucinol reaction...
2017: BioMed Research International
https://www.readbyqxmd.com/read/29147656/polysaccharides-from-trichosanthes-fructus-via-ultrasound-assisted-enzymatic-extraction-using-response-surface-methodology
#17
Fujia Chen, Dahong Li, Hongqi Shen, Chunhong Wang, Enzhong Li, Huihui Xing, Li Guo, Qingchun Zhao, Junhao Shi, Hoang Nguyen, Jiayang Liu
An efficient procedure for ultrasound-assisted enzymatic extraction of crude polysaccharides from Trichosanthes Fructus (crude TFP) using response surface methodology (RSM) was developed. The Box-Behnken design was applied to optimize the effects of pH (X1), enzyme amount (X2), extraction temperature (X3), and liquid-to-solid ratio (X4) on the extraction. The statistical analysis indicated that the independent variables (X4, X2, and X3), the quadratic coefficients (X1(2), X2(2), X3(2), and X4(2)), and the interaction coefficient (X1X3) had significant impact on the yield of crude TFP...
2017: BioMed Research International
https://www.readbyqxmd.com/read/29147097/characterization-of-paenibacillus-sp-mbt213-isolated-from-raw-milk-and-its-ability-to-convert-ginsenoside-rb1-into-ginsenoside-rd-from-panax-ginseng
#18
Gereltuya Renchinkhand, Soo Hyun Cho, Magsar Urgamal, Young W Park, Joong Hyeon Nam, Hyung Churl Bae, Gyu Yong Song, Myoung Soo Nam
This study was conducted to isolate and characterize Paenibacillus sp. MBT213 possessing β-glucosidase activity from raw milk, and examine the enzymatic capacity on the hydrolysis of a major ginsenoside (Rb1). Strain MBT213 was found to have a high hydrolytic ability on ginsenoside Rb1 by Esculin Iron Agar test. 16S rDNA analysis revealed that MBT213 was Paenibacillu sp. Crude enzyme of MBT213 strain exhibited high conversion capacity on ginsenoside Rb1 into ginsenoside Rd proven by TLC and HPLC analyses. The API ZYM kit confirmed that Paenibacillu sp...
2017: Korean Journal for Food Science of Animal Resources
https://www.readbyqxmd.com/read/29147002/capturing-an-initial-intermediate-during-the-p450nor-enzymatic-reaction-using-time-resolved-xfel-crystallography-and-caged-substrate
#19
Takehiko Tosha, Takashi Nomura, Takuma Nishida, Naoya Saeki, Kouta Okubayashi, Raika Yamagiwa, Michihiro Sugahara, Takanori Nakane, Keitaro Yamashita, Kunio Hirata, Go Ueno, Tetsunari Kimura, Tamao Hisano, Kazumasa Muramoto, Hitomi Sawai, Hanae Takeda, Eiichi Mizohata, Ayumi Yamashita, Yusuke Kanematsu, Yu Takano, Eriko Nango, Rie Tanaka, Osamu Nureki, Osami Shoji, Yuka Ikemoto, Hironori Murakami, Shigeki Owada, Kensuke Tono, Makina Yabashi, Masaki Yamamoto, Hideo Ago, So Iwata, Hiroshi Sugimoto, Yoshitsugu Shiro, Minoru Kubo
Time-resolved serial femtosecond crystallography using an X-ray free electron laser (XFEL) in conjunction with a photosensitive caged-compound offers a crystallographic method to track enzymatic reactions. Here we demonstrate the application of this method using fungal NO reductase, a heme-containing enzyme, at room temperature. Twenty milliseconds after caged-NO photolysis, we identify a NO-bound form of the enzyme, which is an initial intermediate with a slightly bent Fe-N-O coordination geometry at a resolution of 2...
November 17, 2017: Nature Communications
https://www.readbyqxmd.com/read/29146475/electrical-activity-of-sensory-pathways-in-female-and-male-geriatric-rhesus-monkeys-macaca-mulatta-and-its-relation-to-oxidative-stress
#20
A Ibáñez-Contreras, U Hernández-Arciga, A Poblano, M Arteaga-Silva, B Hernández-Godínez, G I Mendoza-Cuevas, R Toledo-Pérez, A Alarcón-Aguilar, V Y González-Puertos, M Konigsberg
Synapses loss during aging has been related to decreased neuronal excitability and reduced electrophysiological activity in the nervous system, as well as to increased brain damage. Those physiological and biochemical alterations have been related to the oxidative stress increase associated with old age. The main substrate of lipid peroxidation (LPX) in the central and peripheral nervous systems are the myelin sheaths, and their damage generates a delayed nerve conduction velocity. However, studies in which the neural conduction velocity is related to changes in the redox state are still lacking...
November 13, 2017: Experimental Gerontology
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