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https://www.readbyqxmd.com/read/27913850/two-novel-cyclic-hexapeptides-from-the-genetically-engineered-actinosynnema-pretiosum
#1
Chunhua Lu, Fei Xie, Chuan Shan, Yuemao Shen
Two novel cyclic hexapeptides designated actinosynneptides A (1) and B (2), together with three tryptophan containing diketopiperazines, namely cyclo(L-Trp-L-Trp) (3), cyclo(L-Trp-N-MeL-Trp) (4), and cyclo(N-MeL-Trp-N-MeL-Trp) (5), were isolated from the culture of the genetically engineered strain HGF052::asm18 derived from Actinosynnema pretiosum ATCC31565. Their structures were elucidated on the basis of spectroscopic analyses and single-crystal X-ray diffractions. Compound 1 is the first example of 3-amino-6-hydroxy-2-piperidone-containing cyclic peptides, and 1 and 2 showed moderate cytotoxic activities against HeLa and PC3 cell lines...
December 2, 2016: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/27912176/novel-designed-vmct1-analogs-with-increased-antimicrobial-activity
#2
Cibele Nicolaski Pedron, Marcelo Der Torossian Torres, Julia Aparecida da Silva Lima, Pedro Ismael Silva, Fernanda Dias Silva, Vani Xavier Oliveira
Antimicrobial peptides are biologically active molecules produced by a wide range of organisms as an essential component of the innate immune response. They have recently attracted great interest, since they have antimicrobial activity against a broad spectrum of microorganisms. VmCT1 is a cationic peptide from the venom of Vaejovis mexicanus smithi scorpions, which presents antibacterial activity and tends to helical structures. Its analogs were synthesized, characterized and the conformational studies were performed by circular dichroism...
November 24, 2016: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/27909876/sonochemical-effect-on-activity-and-conformation-of-commercial-lipases
#3
Shamraja S Nadar, Virendra K Rathod
The enzyme under lower-intensity ultrasonic irradiation leads to favourable conformational changes, thereby enhancing its activity. The augmentation of activity of ultrasound-treated enzyme is strongly dependent on ultrasound intensity, duty cycle and exposure time, which was investigated for commercial lipases. Thermomyces lanuginosus (TL) lipase showed a 1.3-fold enhanced activity after irradiating at 22 kHz and 11.38 W cm(-2) with 50 % duty cycle for 25-min ultrasonic treatment and 1.5-fold enhanced activity was observed for lipozyme (candida antarctica lipase B (CALB)) lipase, at 22 kHz and 15...
December 1, 2016: Applied Biochemistry and Biotechnology
https://www.readbyqxmd.com/read/27909574/characterization-of-5-2-18-f-fluoroethoxy-l-tryptophan-for-pet-imaging-of-the-pancreas
#4
Ahmed Abbas, Christine Beamish, Rebecca McGirr, John Demarco, Neil Cockburn, Dawid Krokowski, Ting-Yim Lee, Michael Kovacs, Maria Hatzoglou, Savita Dhanvantari
Purpose: In diabetes, pancreatic beta cell mass declines significantly prior to onset of fasting hyperglycemia. This decline may be due to endoplasmic reticulum (ER) stress, and the system L amino acid transporter LAT1 may be a biomarker of this process. In this study, we used 5-(2- (18)F-fluoroethoxy)-L-tryptophan ( (18)F-L-FEHTP) to target LAT1 as a potential biomarker of beta cell function in diabetes. Procedures: Uptake of (18)F-L-FEHTP was determined in wild-type C57BL/6 mice by ex vivo biodistribution...
2016: F1000Research
https://www.readbyqxmd.com/read/27908238/thermodynamic-analysis-of-fast-stages-of-specific-lesion-recognition-by-dna-repair-enzymes
#5
REVIEW
N A Kuznetsov, O S Fedorova
The methodology of determination of the thermodynamic parameters of fast stages of recognition and cleavage of DNA substrates is described for the enzymatic processes catalyzed by DNA glycosylases Fpg and hOGG1 and AP endonuclease APE1 during base excision repair (BER) pathway. For this purpose, stopped-flow pre-steady-state kinetic analysis of tryptophan fluorescence intensity changes in proteins and fluorophores in DNA substrates was performed at various temperatures. This approach made it possible to determine the changes of standard Gibbs free energy, enthalpy, and entropy of sequential steps of DNA-substrate binding, as well as activation enthalpy and entropy for the transition complex formation of the catalytic stage...
October 2016: Biochemistry. Biokhimii︠a︡
https://www.readbyqxmd.com/read/27907896/harnessing-human-adar2-for-rna-repair-recoding-a-pink1-mutation-rescues-mitophagy
#6
Jacqueline Wettengel, Philipp Reautschnig, Sven Geisler, Philipp J Kahle, Thorsten Stafforst
Site-directed A-to-I RNA editing is a technology for re-programming genetic information at the RNA-level. We describe here the first design of genetically encodable guideRNAs that enable the re-addressing of human ADAR2 toward specific sites in user-defined mRNA targets. Up to 65% editing yield has been achieved in cell culture for the recoding of a premature Stop codon (UAG) into tryptophan (UIG). In the targeted gene, editing was very specific. We applied the technology to recode a recessive loss-of-function mutation in PINK1 (W437X) in HeLa cells and showed functional rescue of PINK1/Parkin-mediated mitophagy, which is linked to the etiology of Parkinson's disease...
October 7, 2016: Nucleic Acids Research
https://www.readbyqxmd.com/read/27907873/excellent-storage-stability-and-sensitive-detection-of-neurotoxin-quinolinic-acid
#7
Ranjana Singh, Sunayana Kashyap, Suveen Kumar, Shiju Abraham, Tejendra K Gupta, Arvind M Kayastha, Bansi D Malhotra, Preeti Suman Saxena, Anchal Srivastava, Ranjan K Singh
Quinolinic acid (QA) is a metabolite of tryptophan degradation obtained through kynurenine pathway, produced naturally in the mammalian brain as well as in the human cerebrospinal fluid. The presence of QA ~10-40µM is a clear indicator of many neurological disorders as well as deficiency of vitamin B6 in human being. In the present work; rapid, sensitive and cost-effective bio-electrodes were prepared to detect the trace amount of endogenous neurotoxin (QA). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) studies were carried out to measure the electrochemical response of the fabricated bio-electrodes as a function of QA concentrations...
November 23, 2016: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/27906600/role-of-polysaccharide-and-lipid-in-lipopolysaccharide-induced-prion-protein-conversion
#8
Carol L Ladner-Keay, Marcia LeVatte, David S Wishart
Conversion of native cellular prion protein (PrP(c)) from an α-helical structure to a toxic and infectious β-sheet structure (PrP(Sc)) is a critical step in the development of prion disease. There are some indications that the formation of PrP(Sc) is preceded by a β-sheet rich PrP (PrP(β)) form which is non-infectious, but is an intermediate in the formation of infectious PrP(Sc). Furthermore the presence of lipid cofactors is thought to be critical in the formation of both intermediate-PrP(β) and lethal, infectious PrP(Sc)...
December 1, 2016: Prion
https://www.readbyqxmd.com/read/27906184/1-methyl-tryptophan-attenuates-regulatory-t-cells-differentiation-due-to-the-inhibition-of-estrogen-ido1-mrc2-axis-in-endometriosis
#9
Chunyan Wei, Jie Mei, Lingli Tang, Yukai Liu, Dajin Li, Mingqing Li, Xiaoyong Zhu
Foxp3(+) regulatory T (Treg) cells contribute to the local dysfunctional immune environment in endometriosis, an estrogen-dependent gynecological disease, which affects the function of ectopic endometrial tissue clearance by the immune system. The reason for the high percentage of peritoneal Treg in endometriosis patients is unknown. Here, we show that the proportion of peritoneal Treg cells increases as endometriosis progresses. To determine the probable mechanism, we established a naive T cell-macrophage-endometrial stromal cell (ESC) co-culture system to mimic the peritoneal cavity microenvironment...
December 1, 2016: Cell Death & Disease
https://www.readbyqxmd.com/read/27905596/spectral-pointillism-of-enhanced-raman-scattering-for-accessing-structural-and-conformational-information-on-single-protein
#10
Jean-Emmanuel Clément, Aymeric Leray, Alexandre Bouhelier, Eric Finot
In this contribution, we provide new insights on the temporal fluctuations of surface enhanced Raman spectra (SERS) of large single molecules such as proteins. Because they can only fit partly into small active volume, SERS analysis is referred to spectral pointillism where only protein subdomains are shined and the whole protein landscape is built from the dynamics of successive individual spectra. By applying our approach on bovine serum albumin, we show that single protein subdomains are mostly comprised of three distinct amino acids...
December 1, 2016: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/27904735/urinary-metabolomics-of-young-italian-autistic-children-supports-abnormal-tryptophan-and-purine-metabolism
#11
Federica Gevi, Lello Zolla, Stefano Gabriele, Antonio M Persico
BACKGROUND: Autism spectrum disorder (ASD) is still diagnosed through behavioral observation, due to a lack of laboratory biomarkers, which could greatly aid clinicians in providing earlier and more reliable diagnoses. Metabolomics on human biofluids provides a sensitive tool to identify metabolite profiles potentially usable as biomarkers for ASD. Initial metabolomic studies, analyzing urines and plasma of ASD and control individuals, suggested that autistic patients may share some metabolic abnormalities, despite several inconsistencies stemming from differences in technology, ethnicity, age range, and definition of "control" status...
2016: Molecular Autism
https://www.readbyqxmd.com/read/27904018/impact-of-plasma-kynurenine-level-on-functional-capacity-and-outcome-in-heart-failure%C3%A3-results-from-studies-investigating-co-morbidities-aggravating-heart-failure-sica-hf
#12
Masaaki Konishi, Nicole Ebner, Jochen Springer, Joerg C Schefold, Wolfram Doehner, Thomas Bernd Dschietzig, Stefan D Anker, Stephan von Haehling
BACKGROUND: Kynurenine is a circulating metabolite from the essential amino acid tryptophan. Accelerated degradation of kynurenine in skeletal muscle has been reported to provide an anti-inflammatory effect. The aim of this study was to investigate the association between blood kynurenine and muscle mass/function in patients with heart failure (HF), in whom diseased muscle mass/function plays a pathophysiological role.Methods and Results:Plasma kynurenine was assessed in 249 patients with HF (67±11 years, 21% women) and in 45 controls from the SICA-HF study...
November 30, 2016: Circulation Journal: Official Journal of the Japanese Circulation Society
https://www.readbyqxmd.com/read/27903651/t-cells-encountering-myeloid-cells-programmed-for-amino-acid-dependent-immunosuppression-use-rictor-mtorc2-for-proliferative-checkpoint-decisions
#13
Lee-Ann Van de Velde, Chitra Subramanian, Amber M Smith, Luke Barron, Joseph E Qualls, Geoffrey Neale, Adolfo Alfonso-Pecchio, Suzanne Jackowski, Charles O Rock, Thomas A Wynn, Peter J Murray
Modulation of T cell proliferation and function by immunoregulatory myeloid cells is an essential means of preventing self-reactivity and restoring tissue homeostasis. Consumption of amino acids such as arginine and tryptophan by immunoregulatory macrophages is one pathway that suppresses local T cell proliferation. Using a reduced complexity in vitro macrophage: T cell co-culture system, we show that macrophage Arginase-1 (Arg1) is the only factor required by M2 macrophages to block T cells in G1, and this effect is mediated by L-arginine elimination rather than metabolite generation...
November 30, 2016: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/27902886/lateral-gene-transfer-of-p-cresol-and-indole-producing-enzymes-from-environmental-bacteria-to-mastigamoeba-balamuthi
#14
Eva Nývltová, Robert Šuťák, Vojtěch Žárský, Karel Harant, Ivan Hrdý, Jan Tachezy
p-Cresol and indole are volatile biologically active products of the bacterial degradation of tyrosine and tryptophan, respectively. They are typically produced by bacteria in animal intestines, soil and various sediments. Here, we demonstrate that the free-living eukaryote Mastigamoeba balamuthi and its pathogenic relative Entamoeba histolytica produce significant amounts of indole via tryptophanase activity. Unexpectedly, M. balamuthi also produces p-cresol in concentrations that are bacteriostatic to non-p-cresol-producing bacteria...
November 30, 2016: Environmental Microbiology
https://www.readbyqxmd.com/read/27899931/melatonin-in-plants-and-plant-culture-systems-variability-stability-and-efficient-quantification
#15
Lauren A E Erland, Abhishek Chattopadhyay, Andrew Maxwell P Jones, Praveen K Saxena
Despite growing evidence of the importance of melatonin and serotonin in the plant life, there is still much debate over the stability of melatonin, with extraction and analysis methods varying greatly from lab to lab with respect to time, temperature, light levels, extraction solvents, and mechanical disruption. The variability in methodology has created conflicting results that confound the comparison of studies to determine the role of melatonin in plant physiology. We here describe a fully validated method for the quantification of melatonin, serotonin and their biosynthetic precursors: tryptophan, tryptamine and N-acetylserotonin by liquid chromatography single quadrupole mass spectrometry (LC-MS) in diverse plant species and tissues...
2016: Frontiers in Plant Science
https://www.readbyqxmd.com/read/27899666/structures-of-human-srp72-complexes-provide-insights-into-srp-rna-remodeling-and-ribosome-interaction
#16
Matthias M M Becker, Karine Lapouge, Bernd Segnitz, Klemens Wild, Irmgard Sinning
Co-translational protein targeting and membrane protein insertion is a fundamental process and depends on the signal recognition particle (SRP). In mammals, SRP is composed of the SRP RNA crucial for SRP assembly and function and six proteins. The two largest proteins SRP68 and SRP72 form a heterodimer and bind to a regulatory site of the SRP RNA. Despite their essential roles in the SRP pathway, structural information has been available only for the SRP68 RNA-binding domain (RBD). Here we present the crystal structures of the SRP68 protein-binding domain (PBD) in complex with SRP72-PBD and of the SRP72-RBD bound to the SRP S domain (SRP RNA, SRP19 and SRP68) detailing all interactions of SRP72 within SRP...
November 29, 2016: Nucleic Acids Research
https://www.readbyqxmd.com/read/27896446/biocompatible-silver-nanoparticles-prepared-with-amino-acids-and-a-green-method
#17
Ricardo Almeida de Matos, Lilia Coronato Courrol
The synthesis of nanoparticles is usually carried out by chemical reduction, which is effective but uses many toxic substances, making the process potentially harmful to the environment. Hence, as part of the search for environmentally friendly or green synthetic methods, this study aimed to produce silver nanoparticles (AgNPs) using only AgNO3, Milli-Q water, white light from a xenon lamp (Xe) and amino acids. Nanoparticles were synthetized using 21 amino acids, and the shapes and sizes of the resultant nanoparticles were evaluated...
November 28, 2016: Amino Acids
https://www.readbyqxmd.com/read/27896310/preservation-of-essential-odor-guided-behaviors-and-odor-based-reversal-learning-after-targeting-adult-brain-serotonin-synthesis
#18
Kaitlin S Carlson, Meredith S Whitney, Marie A Gadziola, Evan S Deneris, Daniel W Wesson
The neurotransmitter serotonin (5-HT) is considered a powerful modulator of sensory system organization and function in a wide range of animals. The olfactory system is innervated by midbrain 5-HT neurons into both its primary and secondary odor-processing stages. Facilitated by this circuitry, 5-HT and its receptors modulate olfactory system function, including odor information input to the olfactory bulb. It is unknown, however, whether the olfactory system requires 5-HT for even its most basic behavioral functions...
September 2016: ENeuro
https://www.readbyqxmd.com/read/27895654/a-comprehensive-phylogeny-reveals-functional-conservation-of-the-uv-b-photoreceptor-uvr8-from-green-algae-to-higher-plants
#19
María B Fernández, Vanesa Tossi, Lorenzo Lamattina, Raúl Cassia
Ultraviolet-B (UV-B) is present in sunlight (280-315 nm) and has diverse effects on living organisms. Low fluence rate of exposure induces a specific photomorphogenic response regulated by the UV-B response locus 8 (UVR8) receptor. UVR8 was first described in Arabidopsis thaliana. In the absence of stimuli it is located in the cytoplasm as a homodimer. However, upon UV-B irradiation, it switches to a monomer and interacts with the ubiquitin ligase E3 COP1 via the UVR8 β-propeller domain and the VP core. This induces the expression of the transcription factor HY5 leading to changes in the expression of genes associated with UV-B acclimation and stress tolerance...
2016: Frontiers in Plant Science
https://www.readbyqxmd.com/read/27894843/mir-509-5p-suppresses-the-proliferation-migration-and-invasion-of-non-small-cell-lung-cancer-by-targeting-ywhag
#20
Peng Wang, Yu Deng, XiangNing Fu
Dysregulation of microRNAs (miRNAs) expression is prevalent in human malignancy development and progression. As previously reported, miR-509-5p has been identified as a tumor suppressor in various cancers, but its role and functional mechanism in NSCLC remains unknown. In the present study, we found that miR-509-5p was significantly downregulated in non-small lung cancer (NSCLC) tissues and cell lines using Quantitative real-time PCR (qRT-PCR). In addition, overexpression of miR-509-5p markedly inhibited the proliferation, migration, invasion and phosphorylation of Akt of NSCLC cells...
November 25, 2016: Biochemical and Biophysical Research Communications
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