Synthesis of new fluorescent amino acids with a triazolopyridine core: diacid sensors

2018 ◽  
Vol 42 (17) ◽  
pp. 14597-14601 ◽  
Author(s):  
L. Chiassai ◽  
R. Ballesteros-Garrido ◽  
R. Ballesteros ◽  
B. Abarca
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
New Family ◽  
Catalysed Reaction ◽  
Fluorescent Amino Acids

A new family of amino acid containing pyridine–triazolopyridine cores has been prepared by means of a copper catalysed reaction.

scholarly journals The heterodimeric amino acid transporter 4F2hc/y+LAT2 mediates arginine efflux in exchange with glutamine

2000 ◽  
Vol 349 (3) ◽  
pp. 787-795 ◽  
Author(s):  
Angelika BRÖER ◽  
Carsten A. WAGNER ◽  
Florian LANG ◽  
Stefan BRÖER
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Mammalian Cells ◽  
Substrate Inhibition ◽  
Cell Types ◽  
Xenopus Laevis Oocytes ◽  
Cationic Amino Acid ◽  
New Family ◽  
Arginine Uptake ◽  
Intracellular Binding

The cationic amino acid arginine, due to its positive charge, is usually accumulated in the cytosol. Nevertheless, arginine has to be released by a number of cell types, e.g. kidney cells, which supply other organs with this amino acid, or the endothelial cells of the blood–brain barrier which release arginine into the brain. Arginine release in mammalian cells can be mediated by two different transporters, y+LAT1 and y+LAT2. For insertion into the plasma membrane, these transporters have to be associated with the type-II membrane glycoprotein 4F2hc [Torrents, Estevez, Pineda, Fernandez, Lloberas, Shi, Zorzano and Palacin (1998) J. Biol. Chem. 273, 32437–32445]. The present study elucidates the function and distribution of y+LAT2. In contrast to y+LAT1, which is expressed mainly in kidney epithelial cells, lung and leucocytes, y+LAT2 has a wider tissue distribution, including brain, heart, testis, kidney, small intestine and parotis. When co-expressed with 4F2hc in Xenopus laevis oocytes, y+LAT2 mediated uptake of arginine, leucine and glutamine. Arginine uptake was inhibited strongly by lysine, glutamate, leucine, glutamine, methionine and histidine. Mutual inhibition was observed when leucine or glutamine was used as substrate. Inhibition of arginine uptake by neutral amino acids depended on the presence of Na+, which is a hallmark of y+LAT-type transporters. Although arginine transport was inhibited strongly by glutamate, this anionic amino acid was only weakly transported by 4F2hc/y+LAT2. Amino acid transport via 4F2hc/y+LAT2 followed an antiport mechanism similar to the other members of this new family. Only preloaded arginine could be released in exchange for extracellular amino acids, whereas marginal release of glutamine or leucine was observed under identical conditions. These results indicated that arginine has the highest affinity for the intracellular binding site and that arginine release may be the main physiological function of this transporter.

Dietary intake of tryptophan tied emotion-related impulsivity in humans

2019 ◽  
pp. 1-8 ◽  
Author(s):  
Florian Javelle ◽  
Descartes Li ◽  
Philipp Zimmer ◽  
Sheri L. Johnson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Intake ◽  
Essential Amino Acid ◽  
Food Habits ◽  
Psychological Disorder ◽  
Serotonin Synthesis ◽  
Amino Acid Tryptophan ◽  
Pass Through ◽  
Three Factor

Abstract. Emotion-related impulsivity, defined as the tendency to say or do things that one later regret during periods of heightened emotion, has been tied to a broad range of psychopathologies. Previous work has suggested that emotion-related impulsivity is tied to an impaired function of the serotonergic system. Central serotonin synthesis relies on the intake of the essential amino acid, tryptophan and its ability to pass through the blood brain barrier. Objective: The aim of this study was to determine the association between emotion-related impulsivity and tryptophan intake. Methods: Undergraduate participants (N = 25, 16 women, 9 men) completed a self-rated measure of impulsivity (Three Factor Impulsivity Index, TFI) and daily logs of their food intake and exercise. These data were coded using the software NutriNote to evaluate intakes of tryptophan, large neutral amino acids, vitamins B6/B12, and exercise. Results: Correlational analyses indicated that higher tryptophan intake was associated with significantly lower scores on two out of three subscales of the TFI, Pervasive Influence of Feelings scores r =  –.502, p < . 010, and (lack-of) Follow-Through scores, r =  –.407, p < . 050. Conclusion: Findings provide further evidence that emotion-related impulsivity is correlated to serotonergic indices, even when considering only food habits. It also suggests the need for more research on whether tryptophan supplements might be beneficial for impulsive persons suffering from a psychological disorder.

Purification of Antihemophilic Factor (Factor VIII) by Amino Acid Precipitation*

1964 ◽  
Vol 11 (01) ◽  
pp. 064-074 ◽  
Author(s):  
Robert H Wagner ◽  
William D McLester ◽  
Marion Smith ◽  
K. M Brinkhous
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Factor Viii ◽  
Plasma Protein ◽  
Acid Precipitation ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Specific Procedure ◽  
Beta Alanine ◽  
Antihemophilic Factor

Summary1. The use of several amino acids, glycine, alpha-aminobutyric acid, alanine, beta-alanine, and gamma-aminobutyric acid, as plasma protein precipitants is described.2. A specific procedure is detailed for the preparation of canine antihemophilic factor (AHF, Factor VIII) in which glycine, beta-alanine, and gammaaminobutyric acid serve as the protein precipitants.3. Preliminary results are reported for the precipitation of bovine and human AHF with amino acids.

Complete Covalent Structure of Human Platelet Factor 4

1979 ◽  
Vol 42 (05) ◽  
pp. 1652-1660 ◽  
Author(s):  
Francis J Morgan ◽  
Geoffrey S Begg ◽  
Colin N Chesterman
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Human Platelet ◽  
Platelet Factor 4 ◽  
Platelet Factor ◽  
Disulphide Bonds ◽  
Covalent Structure

SummaryThe amino acid sequence of the subunit of human platelet factor 4 has been determined. Human platelet factor 4 consists of identical subunits containing 70 amino acids, each with a molecular weight of 7,756. The molecule contains no methionine, phenylalanine or tryptophan. The proposed amino acid sequence of PF4 is: Glu-Ala-Glu-Glu-Asp-Gly-Asp-Leu-Gln-Cys-Leu-Cys-Val-Lys-Thr-Thr-Ser- Gln-Val-Arg-Pro-Arg-His-Ile-Thr-Ser-Leu-Glu-Val-Ile-Lys-Ala-Gly-Pro-His-Cys-Pro-Thr-Ala-Gin- Leu-Ile-Ala-Thr-Leu-Lys-Asn-Gly-Arg-Lys-Ile-Cys-Leu-Asp-Leu-Gln-Ala-Pro-Leu-Tyr-Lys-Lys- Ile-Ile-Lys-Lys-Leu-Leu-Glu-Ser. From consideration of the homology with p-thromboglobulin, disulphide bonds between residues 10 and 36 and between residues 12 and 52 can be inferred.

Single Amino Acid Based Self-Assemblies of Cysteine and Methionine

2018 ◽  
Author(s):  
Nidhi Gour ◽  
Bharti Koshti ◽  
Chandra Kanth P. ◽  
Dhruvi Shah ◽  
Vivek Shinh Kshatriya ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Self Assembly ◽  
Aromatic Amino Acids ◽  
Neutral Condition ◽  
Single Amino Acid ◽  
Binding Assays ◽  
Human Neuroblastoma ◽  
Cytotoxicity Assays ◽  
First Time

We report for the very first time self-assembly of Cysteine and Methionine to discrenible strucutres under neutral condition. To get insights into the structure formation, thioflavin T and Congo red binding assays were done which revealed that aggregates may not have amyloid like characteristics. The nature of interactions which lead to such self-assemblies was purported by coincubating assemblies in urea and mercaptoethanol. Further interaction of aggregates with short amyloidogenic dipeptide diphenylalanine (FF) was assessed. While cysteine aggregates completely disrupted FF fibres, methionine albeit triggered fibrillation. The cytotoxicity assays of cysteine and methionine structures were performed on Human Neuroblastoma IMR-32 cells which suggested that aggregates are not cytotoxic in nature and thus, may not have amyloid like etiology. The results presented in the manuscript are striking, since to the best of our knowledge,this is the first report which demonstrates that even non-aromatic amino acids (cysteine and methionine) can undergo spontaneous self-assembly to form ordered aggregates.

Sign in / Sign up

Export Citation Format

Share Document