METABOLISM OF AROMATIC COMPOUNDS IN HEALTHY AND RUST-INFECTED PRIMARY LEAVES OF WHEAT: I. STUDIES WITH 14CO2, QUINATE-U-14C, AND SHIKIMATE-U-14C AS PRECURSORS

1967 ◽  
Vol 45 (6) ◽  
pp. 863-889 ◽  
Author(s):  
R. Rohringer ◽  
A. Fuchs ◽  
J. Lunderstädt ◽  
D. J. Samborski
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Stem Rust ◽  
Aromatic Compounds ◽  
Alternative Pathway ◽  
Aromatic Amino Acids ◽  
Insoluble Residue ◽  
Near Isogenic Lines ◽  
Acid Fraction ◽  
Wheat Leaves

Healthy and stem rust infected leaves of two near-isogenic lines of wheat were allowed to metabolize 14CO2, quinate-U-14C, or shikimate-U-14C for 22 h in the light.Quinate-U-14C and shikimate-U-14C were interconvertible but differed in their efficiency as precursors of phenylalanine and tyrosine, suggesting that an alternative pathway, not via shikimate, exists from quinate to phenylalanine in wheat leaves. Activity from the cyclites was not incorporated into tryptophan during the metabolic period. Evidently, synthesis of aromatic amino acids in wheat leaves is not restricted to the "classic" shikimate pathway.Infection with rust led to an increase of the carbon How from CO2 to shikimate and to higher levels of both quinate and shikimate. This trend was more pronounced in susceptible than in resistant leaves. Moreover, utilization of quinate and shikimate was increased in infected susceptible leaves but was not altered significantly in infected resistant leaves. Resistant and susceptible reacting leaves differed in the distribution of activity derived from quinate-U-14C and shikiniate-U-14C. With shikimate-U-14C as precursor, resistant reacting leaves accumulated activity in unidentified components of the amino acid fraction (Amberlite IR-120 eluate). Susceptible reacting leaves accumulated less activity in these compounds, and healthy leaves contained only traces of activity in them. When either quinate-U-14C or shikimate-U-14C was metabolized by healthy leaves, more activity was recovered in insoluble esters (of ferulate and p-coumarate) than in soluble esters. Resistant reacting leaves accumulated still more activity in the insoluble esters, whereas susceptible reacting leaves contained a proportionately higher amount of activity in soluble esters. Compared with healthy leaves, susceptible reacting leaves always contained less activity, and resistant reacting leaves more activity, in the non-hydrolyzable, insoluble residue.

METABOLISM OF AROMATIC COMPOUNDS IN HEALTHY AND RUST-INFECTED PRIMARY LEAVES OF WHEAT: II. STUDIES WITH L-PHENYLALANINE-U-14C, L-TYROSINE-U-14C, AND FERULATE-U-14C

1967 ◽  
Vol 45 (11) ◽  
pp. 2137-2153 ◽  
Author(s):  
A. Fuchs ◽  
R. Rohringer ◽  
D. J. Samborski
Keyword(s):  
Amino Acids ◽  
Stem Rust ◽  
Aromatic Compounds ◽  
The Other ◽  
Major Portion ◽  
Insoluble Residue ◽  
Resistant Reaction ◽  
Wheat Leaves

Wheat leaves infected with stem rust, especially those of susceptible plants, contained more phenylalanine and tyrosine than healthy leaves. The utilization of phenylalanine was increased in both the susceptible and resistant reaction, but the utilization of tyrosine was increased only in the susceptible reaction. No evidence of interconversion of these amino acids was obtained.In n-butanol extracts, which contained glycosides, many constituents were labelled after feeding of L-phenylalanine-U-14C. Most of the n-butanol extractives from resistant-reacting leaves contained more label than those from susceptible-reacting leaves or from healthy leaves. However, one of the n-butanol extractives from susceptible-reacting leaves was 5–10 times as active as that isolated from the other tissues.With L-phenylalanine-U-14C and ferulate-U-14C as precursors, more activity was recovered in insoluble than in soluble esters (of ferulate and p-coumarate). With L-tyrosine-U-14C as precursor, the reverse was observed. After infection, the proportion of label in insoluble esters increased more in resistant leaves than it did in susceptible leaves, regardless of the precursor used.A major portion of the activity from these precursors was recovered in the insoluble residue that contained protein and other polymers. In the experiment with L-phenylalanine-U-14C, this residue was fractionated into protein and non-hydrolyzable material. Susceptible-reacting leaves contained equal amounts of activity in these fractions, while resistant-reacting leaves incorporated 2.5 times as much activity into the non-hydrolyzable material as into protein.

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.

Characterization of an isozyme of S-adenosylmethionine synthetase from rat liver

1984 ◽  
Vol 62 (5) ◽  
pp. 276-279 ◽  
Author(s):  
C. H. Lin ◽  
W. Chung ◽  
K. P. Strickland ◽  
A. J. Hudson
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Enzymatic Synthesis ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Aromatic Amino Acids ◽  
Adenosylmethionine Synthetase ◽  
Cellulose Column

An isozyme of S-adenosylmethionine synthetase has been purified to homogeneity by ammonium sulfate fractionation, DEAE-cellulose column chromatography, and gel filtration on a Sephadex G-200 column. The purified enzyme is very unstable and has a molecular weight of 120 000 consisting of two identical subunits. Amino acid analysis on the purified enzyme showed glycine, glutamate, and aspartate to be the most abundant and the aromatic amino acids to be the least abundant. It possesses tripolyphosphatase activity which can be stimulated five to six times by S-adenosylmethionine (20–40 μM). The findings support the conclusion that an enzyme-bound tripolyphosphate is an obligatory intermediate in the enzymatic synthesis of S-adenosylmethionine from ATP and methionine.

scholarly journals Involvement of calcium-sensing receptor activation in the alleviation of intestinal inflammation in a piglet model by dietary aromatic amino acid supplementation

2018 ◽  
Vol 120 (12) ◽  
pp. 1321-1331 ◽  
Author(s):  
Hongnan Liu ◽  
Bie Tan ◽  
Bo Huang ◽  
Jianjun Li ◽  
Jing Wang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Inflammatory Cytokines ◽  
Intestinal Inflammation ◽  
Aromatic Amino Acids ◽  
Dietary Supplementation ◽  
Basal Diet ◽  
Signalling Pathway ◽  
Protein Levels ◽  
Pro Inflammatory Cytokines

AbstractCa2+-sensing receptor (CaSR) represents a potential therapeutic target for inflammatory bowel diseases and strongly prefers aromatic amino acid ligands. We investigated the regulatory effects of dietary supplementation with aromatic amino acids – tryptophan, phenylalanine and tyrosine (TPT) – on the CaSR signalling pathway and intestinal inflammatory response. The in vivo study was conducted with weanling piglets using a 2 × 2 factorial arrangement in a randomised complete block design. Piglets were fed a basal diet or a basal diet supplemented with TPT and with or without inflammatory challenge. The in vitro study was performed in porcine intestinal epithelial cell line to investigate the effects of TPT on inflammatory response using NPS-2143 to inhibit CaSR. Dietary supplementation of TPT alleviated histopathological injury and decreased myeloperoxidase activity in intestine challenged with lipopolysaccharide. Dietary supplementation of TPT decreased serum concentration of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, IL-12, granulocyte-macrophage colony-stimulating factor, TNF-α), as well as the mRNA abundances of pro-inflammatory cytokines in intestine but enhanced anti-inflammatory cytokines IL-4 and transforming growth factor-β mRNA levels compared with pigs fed control diet and infected by lipopolysaccharide. Supplementation of TPT increased CaSR and phospholipase Cβ2 protein levels, but decreased inhibitor of NF-κB kinase α/β and inhibitor of NF-κB (IκB) protein levels in the lipopolysaccharide-challenged piglets. When the CaSR signalling pathway was blocked by NPS-2143, supplementation of TPT decreased the CaSR protein level, but enhanced phosphorylated NF-κB and IκB levels in IPEC-J2 cells. To conclude, supplementation of aromatic amino acids alleviated intestinal inflammation as mediated through the CaSR signalling pathway.

scholarly journals Комбинационное рассеяние света в хирально чистых и рацемической фазах поликристаллов триптофана и тирозина

2019 ◽  
Vol 127 (10) ◽  
pp. 541
Author(s):  
В.С. Горелик ◽  
М.Ф. Умаров ◽  
Ю.П. Войнов
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Raman Spectra ◽  
Spectral Range ◽  
Phase State ◽  
Source Parameters ◽  
Low Frequency ◽  
Aromatic Amino Acids ◽  
Chiral Phase ◽  
Left Handed

AbstractRaman spectra of tryptophan and tyrosine polycrystals have been analyzed in a wide spectral range by fiber-optic spectroscopy. The Raman spectra have been recorded with a BWS465-785H spectrometer in the spectral range of 0–2700 cm^–1 using a 785-nm cw laser as an excitation source. Parameters of the Raman spectra are compared for three crystalline phase modifications of aromatic amino acids: left-handed, right-handed, and racemic phase. The presence of strong Raman satellites, the characteristics of which change depending on the type of the chiral phase state of amino acid, is found in the low-frequency Raman spectra of tryptophan and tyrosine amino acid lattices. The results obtained can be used for monitoring the chiral purity of bioactive preparations containing amino acids.

scholarly journals Specificity of Base-Amino Acid Interactions in Protein-DNA Recognition : Long and Aromatic Amino Acids

2001 ◽  
Vol 41 (supplement) ◽  
pp. S184
Author(s):  
M.M. Gromiha ◽  
K. Sayano ◽  
H. Kono ◽  
M. Aida ◽  
A. Sarai
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dna Recognition ◽  
Aromatic Amino Acids

Transport of L-tyrosine by B16/F10 melanoma cells: the effect of the intracellular content of other amino acids

1990 ◽  
Vol 97 (3) ◽  
pp. 479-485
Author(s):  
J.R. Jara ◽  
J.H. Martinez-Liarte ◽  
F. Solano ◽  
R. Penafiel
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Initial Rate ◽  
Aromatic Amino Acids ◽  
Melanoma Cells ◽  
Transport Systems ◽  
Specific Amino Acid ◽  
Intracellular Content ◽  
Tyrosine Hydroxylation ◽  
In Cells

The uptake of L-Tyr by B16/F10 malignant melanocytes in culture has been studied. These melanoma cells can either be depleted of amino acids by 1 h preincubation in Hanks' isotonic medium or preloaded with a specific amino acid by 1 h preincubation in the same solution containing 2 mM of the amino acid to be preloaded. By means of these pretreatments, it is shown that the rate of L-Tyr uptake is greatly dependent on the content of other amino acids inside the cells. The L-Tyr uptake is higher in cells preloaded with amino acids transported by the L and ASC systems than in cells depleted of amino acids or preloaded with amino acids transported by the A system. It is concluded that L-Tyr is mainly taken up by an exchange mechanism with other amino acids mediated by the L1 system, although the ASC system can also participate in the process. In agreement with that, the homo-exchange performed by cells preloaded with unlabelled L-Tyr is more efficient than any other hetero-exchange, although L-Dopa, the product of tyrosine hydroxylation in melanin synthesis, is almost as efficient as L-Tyr. Apart from aromatic amino acids, melanoma cells preloaded with L-Met and L-His also yield a high initial rate of L-Tyr uptake. The results herein suggest that melanoma cells do not have transport systems specific for L-Tyr, even if this amino acid is needed to carry out the differential pathway of this type of cells, melanosynthesis.

Selective Chemical Deuteration of Aromatic Amino Acids: A Retrospective

1997 ◽  
Author(s):  
K.S. Matthews ◽  
R. Matthews
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aromatic Amino Acid ◽  
Protein Hydrolysate ◽  
Aromatic Amino Acids ◽  
Cellular Protein ◽  
Target Protein ◽  
Chemical Methods ◽  
Lactose Repressor ◽  
Selective Deuteration

In 1970 when we began post-doctoral work in the laboratory of Professor Oleg Jardetzky, selective deuteration of proteins to limit the number of protons present in the system for subsequent analysis was a newly developed and effective technique for NMR exploration of protein structure (Crespi et al., 1968; Markley et al., 1968). This approach allowed more facile assignment of specific resonances and generated the potential to follow the spectroscopic behavior of protons for a specific amino acid sidechain over a broad range of conditions. The primary method for labeling at that time involved growth of microorganisms (generally bacteria or algae) in D2O, followed by isolation of the deuteratedamino acids from a cellular protein hydrolysate. The amino acids isolated were, therefore, completely deuterated. Selective deuteration of a target protein was achieved by growing the producing organism on a mixture of completely deuterated and selected protonated amino acids under conditions that minimized metabolic interconversion of the amino acids. In one-dimensional spectra, aromatic amino acid resonances occur well downfield of the aliphatic resonances, and this region can therefore be examined somewhat independently by utilizing a single protonated aromatic amino acid to simplify the spectrum of the protein. However, the multiple spectral lines generated by aromatic amino acids can be complex and overlapping, precluding unequivocal interpretation. To address this complication, chemical methods were developed to both completely and selectively deuterate side chains of the aromatic amino acids, thereby avoiding the costly necessity of growing large volumes of microorganisms in D2O and subsequent tedious isolation procedures. In addition, selective deuteration of the amino acids simplified the resonance patterns and thereby facilitated assignment and interpretation of spectra. The methods employed were based on exchange phenomena reported in the literature and generated large quantities of material for use in growth of microorganisms for subsequent isolation of selectively labeled protein (Matthews et al., 1977a). The target protein for incorporation of the selectively deuterated aromatic amino acids generated by these chemical methods was the lactose repressor protein from Escherichia coli, and greatly simplified spectra of this 150,000 D protein were produced by this approach.

In Vitro adsorption Spectrum of Plasma Amino Acids by Coated Charcoal Hemoperfusion

1983 ◽  
Vol 6 (5) ◽  
pp. 267-270 ◽  
Author(s):  
Z.Q. Shi ◽  
T.M.S. Chang
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Hepatic Coma ◽  
Aromatic Amino Acids ◽  
Molar Ratio ◽  
Adsorption Experiment ◽  
Preferential Adsorption ◽  
Branched Chain ◽  
Charcoal Hemoperfusion

In order to clarify wether coated charcoal hemoperfusion is capable of normalizing amino acid disturbances in hepatic coma, in vitro adsorption and in vitro hemoperfusion studies were carried out. We have found that collodion-coated activated charcoal beads preferentially removed much more aromatic acids (AAA) than branched chain amino acids (BCAA). In the in vitro adsorption experiment with 50 μM amino acid standards aqueous solution, 99% of AAAs were removed by charcoal while only 50 to 81% of BCAAs were removed. As the concentration of amino acids in solution was doubled from μM to 100 μM, BCAA removal was halved while about 90% of AAA was still being removed. In vitro hemoperfusion with heparinized blood from hepatic failure rats, the clearance and the removal of AAAs were significantly greater than those of BCAAs. Consequently, the molar ratio of BCAA over AAA was markedly improved from the initial 1.09 to 3.87 after 60 min of hemoperfusion. Thus, we have demonstrated the preferential adsorption of aromatic amino acids by collodion-coated charcoal beads. The correction of BCAA/AAA molar ratio is also demonstrated.

Self-healing hydrogels triggered by amino acids

2016 ◽  
Vol 3 (12) ◽  
pp. 1699-1704 ◽  
Author(s):  
Nicola Zanna ◽  
Andrea Merlettini ◽  
Claudia Tomasini
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aspartic Acid ◽  
Chemical Properties ◽  
Aromatic Amino Acids ◽  
Self Healing ◽  
Acidic Amino Acid ◽  
Basic Amino Acids

Nine amino acids with different chemical properties have been chosen to promote the formation of hydrogels based on the bolamphiphilic gelator A: three basic amino acids (arginine, histidine and lysine), one acidic amino acid (aspartic acid), two neutral aliphatic amino acids (alanine and serine) and three neutral aromatic amino acids (phenylalanine, tyrosine and tryptophan).

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