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L-leucine

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https://www.readbyqxmd.com/read/28169479/helical-oligopeptides-of-a-quaternized-amino-acid-with-tunable-chiral-induction-ability-and-an-anomalous-ph-response
#1
Joonil Cho, Yasuhiro Ishida, Takuzo Aida
A series of octamer (8mer) and hexadecamer (16mer) oligopeptides of 4-aminopiperidine-4-carboxylic acid (Api) with L-leucine as a chiral auxiliary at their N- or C-termini were synthesized. Using circular dichroism spectroscopy, the conformational profiles of the peptides were systematically studied, which revealed that the α-helix formation ability of the peptides is determined by the combination of parameters including peptide length, state of the piperidine groups in the Api units, and position of the chiral auxiliary...
February 7, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28163231/effects-of-storage-conditions-on-the-stability-of-spray-dried-inhalable-bacteriophage-powders
#2
Sharon S Y Leung, Thaigarajan Parumasivam, Fiona G Gao, Nicholas B Carrigy, Reinhard Vehring, Warren H Finlay, Sandra Morales, Warwick J Britton, Elizabeth Kutter, Hak-Kim Chan
This study aimed to develop inhalable powders containing phages active against antibiotic-resistant Pseudomonas aeruginosa for pulmonary delivery. A Pseudomonas phage, PEV2, was spray dried into powder matrices comprising of trehalose (0-80%), mannitol (0-80%) and L-leucine (20%). The resulting powders were stored at various relative humidity (RH) conditions (0, 22 and 60% RH) at 4°C. The phage stability and in vitro aerosol performance of the phage powders were examined at the time of production and after 1, 3 and 12 months storage...
February 2, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28118753/protective-effects-of-leucine-on-redox-status-and-mitochondrial-related-gene-abundance-in-the-jejunum-of-intrauterine-growth-retarded-piglets-during-early-weaning-period
#3
Qiang Huang, Wen Xu, Kai-Wen Bai, Jin-Tian He, Hussain Ahmad, Le Zhou, Li-Li Zhang, Tian Wang
The aim of this study was to investigate the effects of dietary supplementation with 0.35% l-leucine on redox status and gene abundance relating to mitochondrial biogenesis and function in the jejunum of intrauterine growth-retarded (IUGR) piglets during early weaning period. According to a 2 × 2 factorial arrangement, 16 IUGR and 16 normal body weight (NBW) piglets were fed a basal diet without l-leucine supplementation or a basal diet plus 0.35% l-leucine supplementation from the age of 14 to 35 d. The results showed that compared with NBW piglets, IUGR piglets had a lower (p < 0...
January 24, 2017: Archives of Animal Nutrition
https://www.readbyqxmd.com/read/28115977/efficacy-of-a-novel-formulation-of-l-carnitine-creatine-and-leucine-on-lean-body-mass-and-functional-muscle-strength-in-healthy-older-adults-a-randomized-double-blind-placebo-controlled-study
#4
Malkanthi Evans, Najla Guthrie, John Pezzullo, Toran Sanli, Roger A Fielding, Aouatef Bellamine
BACKGROUND: Progressive decline in skeletal muscle mass and function are growing concerns in an aging population. Diet and physical activity are important for muscle maintenance but these requirements are not always met. This highlights the potential for nutritional supplementation. As a primary objective, we sought to assess the effect of a novel combination of L-Carnitine, creatine and leucine on muscle mass and performance in older subjects. METHOD: Forty-two healthy older adults aged 55-70 years were randomized to receive either a novel L-Carnitine (1500 mg), L-leucine (2000 mg), creatine (3000 mg), Vitamin D3 (10 μg) (L-Carnitine-combination) product (n = 14), L-Carnitine (1500 mg) (n = 14), or a placebo (n = 14) for eight weeks...
2017: Nutrition & Metabolism
https://www.readbyqxmd.com/read/28091567/quantifying-the-relative-contributions-of-different-solute-carriers-to-aggregate-substrate-transport
#5
Mehdi Taslimifar, Lalita Oparija, Francois Verrey, Vartan Kurtcuoglu, Ufuk Olgac, Victoria Makrides
Determining the contributions of different transporter species to overall cellular transport is fundamental for understanding the physiological regulation of solutes. We calculated the relative activities of Solute Carrier (SLC) transporters using the Michaelis-Menten equation and global fitting to estimate the normalized maximum transport rate for each transporter (Vmax). Data input were the normalized measured uptake of the essential neutral amino acid (AA) L-leucine (Leu) from concentration-dependence assays performed using Xenopus laevis oocytes...
January 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28057466/expression-of-the-alae-gene-is-positively-regulated-by-the-global-regulator-lrp-in-response-to-intracellular-accumulation-of-l-alanine-in-escherichia-coli
#6
Kohei Ihara, Kazuki Sato, Hatsuhiro Hori, Yumiko Makino, Shuji Shigenobu, Tasuke Ando, Emiko Isogai, Hiroshi Yoneyama
The alaE gene in Escherichia coli encodes an l-alanine exporter that catalyzes the active export of l-alanine using proton electrochemical potential. In our previous study, alaE expression was shown to increase in the presence of l-alanyl-l-alanine (Ala-Ala). In this study, the global regulator leucine-responsive regulatory protein (Lrp) was identified as an activator of the alaE gene. A promoter less β-galactosidase gene was fused to an alaE upstream region (240 nucleotides). Cells that were lacZ-deficient and harbored this reporter plasmid showed significant induction of β-galactosidase activity (approximately 17-fold) in the presence of 6 mM l-alanine, l-leucine, and Ala-Ala...
January 3, 2017: Journal of Bioscience and Bioengineering
https://www.readbyqxmd.com/read/28053823/global-metabolic-profiling-of-plasma-shows-that-three-year-mild-caloric-restriction-lessens-an-age-related-increase-in-sphingomyelin-and-reduces-l-leucine-and-l-phenylalanine-in-overweight-and-obese-subjects
#7
Minjoo Kim, Sang-Hyun Lee, Jong Ho Lee
The effect of weight loss from long-term, mild-calorie diets (MCD) on plasma metabolites is unknown. This study was to examine whether MCD-induced weight reduction caused changes in the extended plasma metabolites. Overweight and obese subjects aged 40-59 years consumed a MCD (approximately 100 kcal/day deficit, n=47) or a weight-maintenance diet (control, n=47) in a randomized, controlled design with a three-year clinical intervention period and plasma samples were analyzed by using UPLC-LTQ-Orbitrap mass spectrometry...
December 2016: Aging and Disease
https://www.readbyqxmd.com/read/28034351/synthesis-and-preliminary-evaluation-of-5-18f-fluoroleucine
#8
Bennett B Chin, Darryl McDougald, Douglas Weitzel, Thomas Hawk, Robert E Reiman, Michael R Zalutsky, Ganesan Vaidyanathan
BACKGROUND: Amino acid transporters, such as LAT1, are overexpressed in aggressive prostate and breast carcinomas, directly influencing pathways of growth and proliferation. OBJECTIVE: The purpose of this study is to synthesize and characterize a novel 18F labeled leucine analog, 5-[18F]fluoroleucine, as a potential imaging agent for aggressive tumors which may not be amenable to imaging by FDG PET. METHODS: 5-fluoroleucine was synthesized and characterized, and its 18F-labeled analog was synthesized from a mesylate precursor...
December 30, 2016: Current Radiopharmaceuticals
https://www.readbyqxmd.com/read/28024261/simultaneous-hplc-assay-for-pretomanid-pa-824-moxifloxacin-and-pyrazinamide-in-an-inhaler-formulation-for-drug-resistant-tuberculosis
#9
Mohammad A M Momin, Sim J Thien, Woravimol Krittaphol, Shyamal C Das
A simple and sensitive reversed phase HPLC method has been developed for the simultaneous quantitation of pretomanid (PA-824), moxifloxacin and pyrazinamide in a combination spray-dried powder formulation for inhalation, without any use of an internal standard. Good resolution of the analytes was achieved on a Luna C18 (2), 150×4.6mm, 5μm, 100Å column using gradient elution with a mobile phase containing methanol and triethylamine phosphate buffer (pH 2.5) at a flow rate of 1.0mL/min in a total run time of 25min...
November 25, 2016: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/27989117/hplc-separation-of-sulforaphane-enantiomers-in-broccoli-and-its-sprouts-by-transformation-into-diastereoisomers-using-derivatization-with-s-leucine
#10
Makiko Okada, Atsushi Yamamoto, Sen-Ichi Aizawa, Atsushi Taga, Hiroyuki Terashima, Shuji Kodama
Racemic sulforaphane, which was derivatized with (S)-leucine (l-leucine), was resolved by reversed phase HPLC with UV detection. The optimum mobile phase conditions were found to be 10 mM citric acid (pH 2.8) containing 22% methanol at 35 °C using detection at 254 nm. Sulforaphane enantiomers in florets and stems of five brands of broccoli and leaves and stems of three brands of broccoli sprouts were analyzed by the proposed HPLC method. Both sulforaphane enantiomers were detected in all of the samples. The S/R ratios of sulforaphane in broccoli samples were 1...
December 27, 2016: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/27987784/a-novel-l-leucine-modified-sol-gel-carbon-electrode-for-simultaneous-electrochemical-detection-of-homovanillic-acid-dopamine-and-uric-acid-in-neuroblastoma-diagnosis
#11
Redouan El Khamlichi, Dounia Bouchta, El Hassane Anouar, Mounia Ben Atia, Aisha Attar, Mohamed Choukairi, Saloua Tazi, Raissouni Ihssane, Chaoukat Faiza, Draoui Khalid, Riffi Temsamani Khalid
Neuroblastoma is a pediatric neuroblastic tumor arising in the sympathetic nervous crest cells. A high grade of Neuroblastoma is characterized by a high urinary excretion of homovanillic acid and dopamine. In this work l-leucine modified Sol-Gel-Carbon electrode was used for a sensitive voltammetric determination of homovanillic acid and dopamine in urine. The electrochemical response characteristics were investigated by cyclic and differential pulse voltammetry; the modified electrode has shown an increase in the effective area of up to 40%, a well-separated oxidation peaks and an excellent electrocatalytic activity...
February 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/27986991/recombinant-expression-and-characterization-of-a-l-amino-acid-oxidase-from-the-fungus-rhizoctonia-solani
#12
Katharina Hahn, Katrin Neumeister, Andreas Mix, Tilman Kottke, Harald Gröger, Gabriele Fischer von Mollard
L-Amino acid oxidases (L-AAOs) catalyze the oxidative deamination of L-amino acids to the corresponding α-keto acids, ammonia, and hydrogen peroxide. L-AAOs are homodimeric enzymes with FAD as a non-covalently bound cofactor. They are of potential interest for biotechnological applications. However, heterologous expression has not succeeded in producing large quantities of active recombinant L-AAOs with a broad substrate spectrum so far. Here, we report the heterologous expression of an active L-AAO from the fungus Rhizoctonia solani in Escherichia coli as a fusion protein with maltose-binding protein (MBP) as a solubility tag...
December 16, 2016: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/27981404/two-new-mononuclear-copper-ii-dipeptide-complexes-of-2-2-pyridyl-benzoxazole-dna-interaction-antioxidation-and-in-vitro-cytotoxicity-studies
#13
Qian Gan, Yongyu Qi, Yahong Xiong, Yinlian Fu, Xueyi Le
Two new mononuclear mixed ligand copper(II) complexes [Cu(PBO)(Gly-gly)(H2O)]·ClO4·1.5H2O (1) and [Cu(PBO)(Gly-L-leu)(H2O)]·ClO4 (2) (PBO is 2-(2'-pyridyl)benzoxazole, Gly-gly and Gly-L-leu are Glycyl-glycine anion and Glycyl-L-leucine anion, respectively), have been prepared and characterized by various analytical and spectral techniques. The interactions of the complexes with DNA were investigated using multi-spectroscopic methods (absorption, emission, circular dichroism), viscometry and electrochemical titration as well as molecular docking technique...
December 15, 2016: Journal of Fluorescence
https://www.readbyqxmd.com/read/27940203/cooperative-synthesis-of-dopamine-by-non-dopaminergic-neurons-as-a-compensatory-mechanism-in-the-striatum-of-mice-with-mptp-induced-parkinsonism
#14
Elena A Kozina, Aleksandr R Kim, Anna Y Kurina, Michael V Ugrumov
Since the late 80s it has been repeatedly shown that besides dopaminergic neurons, the brain contains so-called monoenzymatic neurons possessing one of the enzymes of dopamine (DA) synthesis, tyrosine hydroxylase (TH) or aromatic l-amino acid decarboxylase (AADC). However, the data on the existence of monoenzymatic neurons in the striatum remain controversial, and little is known about their functional significance. The aim of this study was to test our hypothesis that monoenzymatic TH-containing neurons produce DA in cooperation with the neurons containing AADC, which might help to compensate DA deficiency under the failure of the nigrostriatal dopaminergic system...
February 2017: Neurobiology of Disease
https://www.readbyqxmd.com/read/27936793/biomimetic-total-synthesis-of-the-pentacyclic-amaryllidaceae-alkaloid-derivative-gracilamine
#15
Nadia Yuqian Gao, Martin G Banwell, Anthony C Willis
The illustrated azomethine ylide, produced through a Schiff base condensation of the corresponding aldehyde-containing C3a-arylhexahydroindole with ethyl l-leucinate, engages in a stereoselective intramolecular cycloaddition reaction to give adduct 23 that has been elaborated, over eight steps, into the racemic modification of the alkaloid derivative gracilamine (1). The formation of this ylide and its conversion into isomer 23 mimics the proposed biogenesis of the pentacyclic framework of compound 1.
December 12, 2016: Organic Letters
https://www.readbyqxmd.com/read/27910839/accurate-hydrogen-parameters-for-the-amino-acid-l-leucine
#16
Jack Binns, Simon Parsons, Garry J McIntyre
The structure of the primary amino acid L-leucine has been determined for the first time by neutron diffraction. This was made possible by the use of modern neutron Laue diffraction to overcome the previously prohibitive effects of crystal size and quality. The packing of the structure into hydrophobic and hydrophilic layers is explained by the intermolecular interaction energies calculated using the PIXEL method. Variable-temperature data collections confirmed the absence of phase transitions between 120 and 300 K in the single-crystal form...
December 1, 2016: Acta Crystallographica Section B, Structural Science, Crystal Engineering and Materials
https://www.readbyqxmd.com/read/27875537/effect-of-l-tryptophan-and-l-leucine-on-gut-hormone-secretion-appetite-feelings-and-gastric-emptying-rates-in-lean-and-non-diabetic-obese-participants-a-randomized-double-blind-parallel-group-trial
#17
Anne Christin Meyer-Gerspach, Simon Häfliger, Julian Meili, Alison Doody, Jens F Rehfeld, Jürgen Drewe, Christoph Beglinger, Bettina Wölnerhanssen
BACKGROUND/OBJECTIVES: Gut hormones such as cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1) play a role as satiation factors. Strategies to enhance satiation peptide secretion could provide a therapeutic approach for obesity. Carbohydrates and lipids have been extensively investigated in relation to peptide release. In contrast, the role of proteins or amino acids is less clear. Our aim was to compare the effects of the amino acids L-tryptophan (L-trp) and L-leucine (L-leu) separately on gastric emptying and gut peptide secretion...
2016: PloS One
https://www.readbyqxmd.com/read/27873181/inhalable-ipratropium-bromide-particle-engineering-with-multicriteria-optimization
#18
Bhavani Prasad Vinjamuri, Rahul V Haware, William C Stagner
Spray-dried ipratropium bromide (IPB) microspheres for oral inhalation were engineered using Quality by Design. The interrogation of material properties, process parameters, and critical product quality attributes interplay enabled rational product design. A 2(7-3) screening design exhibited the Maillard reaction between L-leucine (LL) and lactose at studied outlet temperatures (OT) >130°C. A response surface custom design was used in conjunction with multicriteria optimization to determine the operating design space to achieve inhalable microparticles...
November 21, 2016: AAPS PharmSciTech
https://www.readbyqxmd.com/read/27872960/branched-chain-amino-acids
#19
Keisuke Yamamoto, Atsunari Tsuchisaka, Hideaki Yukawa
Branched-chain amino acids (BCAAs), viz., L-isoleucine, L-leucine, and L-valine, are essential amino acids that cannot be synthesized in higher organisms and are important nutrition for humans as well as livestock. They are also valued as synthetic intermediates for pharmaceuticals. Therefore, the demand for BCAAs in the feed and pharmaceutical industries is increasing continuously. Traditional industrial fermentative production of BCAAs was performed using microorganisms isolated by random mutagenesis. A collection of these classical strains was also scientifically useful to clarify the details of the BCAA biosynthetic pathways, which are tightly regulated by feedback inhibition and transcriptional attenuation...
November 22, 2016: Advances in Biochemical Engineering/biotechnology
https://www.readbyqxmd.com/read/27845719/electrochemical-aptatoxisensor-responses-on-nanocomposites-containing-electro-deposited-silver-nanoparticles-on-poly-propyleneimine-dendrimer-for-the-detection-of-microcystin-lr-in-freshwater
#20
Mawethu P Bilibana, Avril R Williams, Candice Rassie, Christopher E Sunday, Hlamulo Makelane, Lindsay Wilson, Nomaphelo Ntshongontshi, Abongile N Jijana, Milua Masikini, Priscilla G L Baker, Emmanuel I Iwuoha
A sensitive and reagentless electrochemical aptatoxisensor was developed on cobalt (II) salicylaldiimine metallodendrimer (SDD-Co(II)) doped with electro-synthesized silver nanoparticles (AgNPs) for microcystin-LR (L, l-leucine; R, l-arginine), or MC-LR, detection in the nanomolar range. The GCE|SDD-Co(II)|AgNPs aptatoxisensor was fabricated with 5' thiolated aptamer through self-assembly on the modified surface of the glassy carbon electrode (GCE) and the electronic response was measured using cyclic voltammetry (CV)...
November 11, 2016: Sensors
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