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https://www.readbyqxmd.com/read/28937773/probing-the-hiv-1-ncp7-nucleocapsid-protein-with-site-specific-gold-i-phosphine-complexes
#1
Raphael E F de Paiva, Zhifeng Du, Erica J Peterson, Pedro P Corbi, Nicholas P Farrell
In this work, we examined a series of thiophilic Au(I) compounds based on [Au(L)(PR3)] (L = Cl(-), 4-dimethylaminopyridine (dmap); R= ethyl (Et), cyclohexyl (Cy)) for chemoselective auration of the C-terminal HIV nucleocapsid protein NCp7 F2 and the "full" HIV NCp7 (NC, zinc finger (ZnF)) as probes of nucleocapsid topography. The choice of phosphine allowed electronic and steric effects to be considered. The use of the heterocycle "leaving group" allowed us to study the effect of possible π-stacking with the essential tryptophan residue of NC on the reactivity and selectivity, mimicking the naturally occurring interaction between the zinc finger and nucleic acids...
September 22, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28936824/discrimination-of-human-and-nonhuman-blood-using-raman-spectroscopy-with-self-reference-algorithm
#2
Haiyi Bian, Peng Wang, Jun Wang, Huancai Yin, Yubing Tian, Pengli Bai, Xiaodong Wu, Ning Wang, Yuguo Tang, Jing Gao
We report a self-reference algorithm to discriminate human and nonhuman blood by calculating the ratios of identification Raman peaks to reference Raman peaks and choosing appropriate threshold values. The influence of using different reference peaks and identification peaks was analyzed in detail. The Raman peak at 1003  cm-1 was proved to be a stable reference peak to avoid the influencing factors, such as the incident laser intensity and the amount of sample. The Raman peak at 1341  cm-1 was found to be an efficient identification peak, which indicates that the difference between human and nonhuman blood results from the C-H bend in tryptophan...
September 2017: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/28935513/non-invasive-tryptophan-fluorescence-measurements-as-a-novel-method-of-grading-cataract
#3
Jesper Høiberg Erichsen, Aurore Mensah, Line Kessel
Development of non-invasive treatments for cataract calls for a sensitive diagnostic assay. We conducted a study to test whether the ratio of folded tryptophan to non-tryptophan fluorescence emission (F-factor) may be used for grading cataracts in human lenses. The F-factor was measured on aspirated lens material from eyes undergoing femtosecond laser assisted cataract surgery (FLACS) and was compared to a preoperative optical grading of cataract using Scheimpflug imaging. The preoperative optical grading allocated the cataracts to 1 of 4 categories according to the density of the cataract...
September 18, 2017: Experimental Eye Research
https://www.readbyqxmd.com/read/28934309/increased-plasma-proline-concentrations-are-associated-with-sarcopenia-in-the-elderly
#4
Kenji Toyoshima, Marie Nakamura, Yusuke Adachi, Akira Imaizumi, Tomomi Hakamada, Yasuko Abe, Eiji Kaneko, Soiciro Takahashi, Kentaro Shimokado
BACKGROUND AND PURPOSE: Metabolome analyses have shown that plasma amino acid profiles reflect various pathological conditions, such as cancer and diabetes mellitus. It remains unclear, however, whether plasma amino acid profiles change in patients with sarcopenia. This study therefore aimed to investigate whether sarcopenia-specific changes occur in plasma amino acid profiles. METHODS: A total of 153 community-dwelling and seven institutionalized elderly individuals (56 men, 104 women; mean age, 77...
2017: PloS One
https://www.readbyqxmd.com/read/28933662/deficiency-of-serotonin-in-raphe-neurons-and-altered-behavioral-responses-in-tryptophan-hydroxylase-2-knockout-medaka-oryzias-latipes
#5
Satoshi Ansai, Hiroshi Hosokawa, Shingo Maegawa, Kiyoshi Naruse, Youhei Washio, Kenji Sato, Masato Kinoshita
Serotonin (5-hydroxytryptamine [5-HT]) is a bioactive monoamine that acts as a neurotransmitter in the central and peripheral nervous system of animals. Teleost fish species have serotonergic neurons in the raphe nuclei of the brainstem; however, the role of 5-HT in the raphe neurons in teleost fish remains largely unknown. Here, we established a medaka (Oryzias latipes) strain with targeted disruption of tryptophan hydroxylase 2 (tph2) gene that is involved in the 5-HT synthesis in the raphe nuclei. Immunohistochemistry and mass spectrometry analysis revealed that the homozygous mutants (tph2(Δ13/Δ13)) lacked the ability to synthesize 5-HT in the raphe neurons...
September 21, 2017: Zebrafish
https://www.readbyqxmd.com/read/28933348/the-multi-resolution-capability-of-tchebichef-moments-and-its-applications-to-the-analysis-of-fluorescence-excitation-emission-spectra
#6
Baoqiong Li, Xue Wang, Min Li Xu, Hong Lin Zhai, Jing Chen, Jin Jin Liu
Fluorescence spectroscopy with excitation-emission matrix (EEM) is a fast and inexpensive technique and has been applied to the detection of a very wide range of analytes. However, the serious scatterings and overlapping signals hinder the applications of EEM spectra. In this contribution, the multi-resolution capability of Tchebichef moments was investigated deeply and applied to the analysis of two EEM data sets (data set 1 consisted of Valine-tyrosine-Valine, Tryptophan-Glycine and Phenylalanine, and data set 2 included Vitamin B1, Vitamin B2 and Vitamin B6) for the first time...
September 21, 2017: Methods and Applications in Fluorescence
https://www.readbyqxmd.com/read/28932939/the-thumb-domain-is-not-essential-for-the-catalytic-action-of-holama-dna-polymerase
#7
Angela Gala Morena Gatius, Fabrizio Dal Piaz, Alejandro Hochkoeppler
A structural and kinetic characterization of a fragment of the HoLaMa DNA polymerase is presented here. In particular, a truncated form of HoLaMa, devoid of a consistent portion of the thumb domain, was isolated and purified. This HoLaMa fragment, denoted as ΔNter-HoLaMa, is surprisingly competent in catalyzing DNA extension, albeit featuring a kcat one order of magnitude lower than the corresponding kinetic constant of its full-length counterpart. The conformational rearrangements, if any, of enzyme tryptophanes triggered by DNA binding or extension were assayed under pre-steady-state conditions...
September 20, 2017: Protein Journal
https://www.readbyqxmd.com/read/28932251/a-metabolomics-based-strategy-for-the-mechanism-exploration-of-traditional-chinese-medicine-descurainia-sophia-seeds-extract-and-fractions-as-a-case-study
#8
Ning Zhou, Ya-Ping Sun, Xiao-Ke Zheng, Qiu-Hong Wang, Yan-Yun Yang, Zhi-Yao Bai, Hai-Xue Kuang, Wei-Sheng Feng
A UPLC-QTOF-MS based metabolomics research was conducted to explore potential biomarkers which would increase our understanding of the model and to assess the integral efficacy of Descurainia sophia seeds extract (DS-A). Additionally, DS-A was split into five fractions in descending order of polarity, which were utilized to illustrate the mechanism together. The 26 identified biomarkers were mainly related to disturbances in phenylalanine, tyrosine, tryptophan, purine, arginine, and proline metabolism. Furthermore, heat map, hierarchical cluster analysis (HCA), and correlation network diagram of biomarkers perturbed by modeling were all conducted...
2017: Evidence-based Complementary and Alternative Medicine: ECAM
https://www.readbyqxmd.com/read/28931628/type-b-response-regulators-act-as-central-integrators-in-transcriptional-control-of-the-auxin-biosynthesis-enzyme-taa1
#9
Zhenwei Yan, Xin Liu, Karin Ljung, Shuning Li, Wanying Zhao, Fan Yang, Meiling Wang, Yi Tao
During embryogenesis and organ formation, establishing proper gradient is critical for auxin function, which is achieved through coordinated regulation of both auxin metabolism and transport. Expression of auxin biosynthetic genes is often tissue specific and is regulated by environmental signals. However, the underlying regulatory mechanisms remain elusive. Here, we investigated the transcriptional regulation of a key auxin biosynthetic gene, TAA1 (L-Tryptophan aminotransferase of Arabidopsis 1). A canonical and a novel ARR (Arabidopsis response regulators) binding site were identified in the promoter and the second intron of TAA1, which were required for its tissue specific expression...
September 20, 2017: Plant Physiology
https://www.readbyqxmd.com/read/28931605/structural-basis-for-clonal-diversity-of-the-human-t-cell-response-to-a-dominant-influenza-virus-epitope
#10
Xinbo Yang, Guobing Chen, Nan-Ping Weng, Roy A Mariuzza
Influenza A virus (IAV) causes an acute infection in humans that is normally eliminated by CD8+ cytotoxic T lymphocytes. Individuals expressing the major histocompatibility complex (MHC) class I molecule HLA-A2 produce cytotoxic T lymphocytes bearing T cell receptors (TCRs) that recognize the immunodominant IAV epitope GILGFVFTL (GIL). Most GIL-specific TCRs utilize α/β pairs encoded by the TRAV27/TRBV19 gene combination to recognize this relatively featureless peptide epitope (canonical TCRs). However, ~40% of GIL-specific TCRs express a wide variety of other TRAV/TRBV combinations (non-canonical TCRs)...
September 20, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28931312/antidepressive-effects-of-environmental-enrichment-in-chronic-stress-induced-depression-in-rats
#11
Ho-Hyun Seong, Jong-Min Park, Youn-Jung Kim
Depression is caused by a variety of factors, especially stressful life events. Chronic stress-induced depression has detrimental effects on hippocampal integrity. Environmental enrichment (EE) is a beneficial intervention for improving anxiety, fear, and stress. We aimed to investigate the antidepressive effects of EE in a depressive rat model (DEP) that was subjected to chronic stress. The control group ( n = 10) was kept under normal conditions, while depressive rats ( n = 8 per group) were randomized into DEP, DEP + EE, and DEP + fluoxetine (Flx) groups...
January 1, 2017: Biological Research for Nursing
https://www.readbyqxmd.com/read/28930695/metabolomics-assessment-of-the-effects-of-diclofenac-exposure-on-mytilus-galloprovincialis-potential-effects-on-osmoregulation-and-reproduction
#12
Bénilde Bonnefille, Elena Gomez, Mellis Alali, David Rosain, Hélène Fenet, Frédérique Courant
The presence of pharmaceutically active compounds in aquatic environments has become a major concern over the past 20years. Elucidation of their mode of action and effects in non-target organisms is thus now a major ecotoxicological challenge. Diclofenac (DCF) is among the pharmaceutical compounds of interest based on its inclusion in the European Union Water Framework Directive Watch List. In this study, our goal was to investigate the potential of a metabolomic approach to acquire information without any a priori hypothesis about diclofenac effects on marine mussels...
September 17, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28929692/-metabolomics-of-bovine-serum-albumin-induced-allergic-reactions-based-on-uplc-q-tof-ms
#13
Yuan-Yuan Gu, Dan-Dan Zhang, Cheng Feng, Yu Wang, Da-Zhong Chen, Yan-Hong Wang
The metabonomic techniques were used to study the changes in endogenous metabolites between urines of rats in normal physiological conditions and bovine serum albumin induced allergic reactions, identify potential biomarkers associated with allergic reactions, and then analyze the metabolic pathways and the metabolic mechanisms of allergic reactions. The bovine serum albumin-induced allergic reactions in rats were adopted as a model to detect histamine and tryptase in rat serum and observe the issue morphology of lungs and trachea in rats...
November 2016: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/28929654/-chemical-studieson-hydrophilic-constituents-of-toad-skin
#14
Shao-Kun Xin, Nan Si, Hong-Jie Wang, Jian Yang, Bo Gao, Xiao-Lu Wei, Hai-Yu Zhao, Bao-Lin Bian
Fifteen compounds were isolated from the toad skin by a combination of various chromatographic methods including macroporous resin, silica gel, ODS and semi-preparative HPLC. Their structures were identified as 4,5-dimethyl-1,3,4,5-tetrahydropyrrolo[4,3,2-de]quinolin-6-ol(1), serotonin(2), N-methyl serotonin(3), O-methyl bufotenine(4), 1,2,3,4-tetrahydro-6-hydroxy-β-carboline(5), O-methylserotonin(6), glycinebetaine(7), caffeine(8), bufotenine(9), shepherdine(10), tryptophan(11), (5-hydroxy-1H-indol-3-yl)acetic acid(12), 5-hydroxy tryptophol(13), 2-methyl-6-hydroxy-1,2,3,4-tetrahydro-β-carboline(14), bufothionine(15)...
October 2016: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/28929575/development-of-an-optical-sensor-for-chlortetracycline-detection-based-on-the-fluorescence-quenching-of-l-tryptophan
#15
Hui Zhang, Hongyun Chen, Shuang Pan, Huan Yang, Jingjing Yan, Xiaoli Hu
A simple and selective spectrofluorimetric method for the detection of chlortetracycline (CTC) was studied. In pH 7.4 buffer medium l-tryptophan (l-Trp), applied as the fluorescence probe, interacted with CTC resulting in fluorescence quenching of the probe. CTC was detected with maximum excitation and emission wavelengths at λex /λem  = 275/350 nm. Notably, quenching of fluorescence intensities was positively proportional to the CTC concentration over the range of 0.65-30 μmol L(-1) and the limit of detection was 0...
September 20, 2017: Luminescence: the Journal of Biological and Chemical Luminescence
https://www.readbyqxmd.com/read/28928660/-1-h-nmr-based-metabolomics-study-of-the-toxicological-effects-in-rats-induced-by-renqing-mangjue-pill-a-traditional-tibetan-medicine
#16
Can Xu, Caidan Rezeng, Jian Li, Lan Zhang, Yujing Yan, Jian Gao, Yingfeng Wang, Zhongfeng Li, Jianxin Chen
"RenqingMangjue" pill (RMP), as an effective prescription of Traditional Tibetan Medicine (TTM), has been widely used in treating digestive diseases and ulcerative colitis for over a thousand years. In certain classical Tibetan Medicine, heavy metal may add as an active ingredient, but it may cause contamination unintentionally in some cases. Therefore, the toxicity and adverse effects of TTM became to draw public attention. In this study, 48 male Wistar rats were orally administrated with different dosages of RMP once a day for 15 consecutive days, then half of the rats were euthanized on the 15th day and the remaining were euthanized on the 30th day...
2017: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/28928466/magnetic-field-effect-in-natural-cryptochrome-explored-with-model-compound
#17
Shubhajit Paul, Alexey S Kiryutin, Jinping Guo, Konstantin L Ivanov, Jörg Matysik, Alexandra V Yurkovskaya, Xiaojie Wang
Many animals sense the Earth's magnetic-field and use it for navigation. It is proposed that a light-dependent quantum effect in cryptochrome proteins, residing in the retina, allows for such an iron-free spin-chemical compass. The photochemical processes, spin-dynamics and its magnetic field dependence in natural cryptochrome are not fully understood by the in vivo and in vitro studies. For a deeper insight into these biophysical mechanisms in cryptochrome, we had introduced a flavin-tryptophan dyad (F10T)...
September 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28927928/discerning-the-composition-of-penetratin-for-safe-penetration-from-cornea-to-retina
#18
Kuan Jiang, Xin Gao, Qing Shen, Changyou Zhan, Yanyu Zhang, Cao Xie, Gang Wei, Weiyue Lu
Delivery of biomacromolecules into the eye is greatly hindered by several protective barriers. The cell-penetrating peptide, penetratin, has been found to be an effective absorption enhancer for noninvasive intraocular gene delivery. To discern the composition of penetratin for safe penetration from cornea to retina, we designed a series of penetratin derivatives by varying the hydrophobicity and evaluated their potency for retina-targeted delivery. The hydrophilic amino acids of penetratin, excluding the conserved basic amino acid residues, were respectively replaced with tryptophan...
September 16, 2017: Acta Biomaterialia
https://www.readbyqxmd.com/read/28927718/metabolic-profiling-of-the-effects-of-ginsenoside-re-in-an-alzheimer-s-disease-mouse-model
#19
Jingyuan Li, Ying Liu, Wei Li, Zhe Wang, Pan Guo, Lin Li, Naijing Li
Alzheimer's disease (AD) is one of the major neurological diseases among the elderly, and there are presently no approved treatments that can slow its progression. It has been reported that ginsenoside Re (G-Re), an active pharmacological component of ginseng, can ameliorate the symptoms of AD, but the underlying mechanisms are not clear. The current study was designed to test the effects of G-Re by investigating the metabolite profiles of AD mice. An AD animal model was induced by intracerebroventricular injection of β-amyloid in Kunming mice...
September 16, 2017: Behavioural Brain Research
https://www.readbyqxmd.com/read/28927486/hplc-determination-of-total-tryptophan-in-infant-formula-and-adult-pediatric-nutritional-formula-following-enzymatic-hydrolysis-single-laboratory-validation-first-action-2017-03
#20
Jonathan Draher, Norman White
A method for tryptophan (Trp) analysis designed to comply with AOAC Standard Method Performance Requirement 2014.013 is described. Unlike AOAC 988.15, which uses alkaline hydrolysis, this method uses enzymatic hydrolysis to release the Trp from the intact protein. The method achieves an LOQ of 0.18 mg/100 g Trp on a ready-to-feed basis with mean recoveries ranging from 93.8 to 104.9%. Repeatability ranged from 0.2 to 5.0%. Intermediate precision ranged from 1.0 to 6.9%. The analytical range was determined to be 0...
September 19, 2017: Journal of AOAC International
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