Effects of Glyphosate on the Metabolism of Phenolic Compounds: VII. Root-Fed Amino Acids and Glyphosate Toxicity in Soybean (Glycine max) Seedlings

Weed Science ◽  
1981 ◽  
Vol 29 (3) ◽  
pp. 297-302 ◽  
Author(s):  
S. O. Duke ◽  
R. E. Hoagland
Keyword(s):  
Amino Acids ◽  
Glycine Max ◽  
Amino Acid ◽  
Phenolic Compounds ◽  
Aromatic Amino Acid ◽  
Aromatic Amino Acids ◽  
Acid Synthesis ◽  
Root Growth Inhibition ◽  
Shikimate Dehydrogenase ◽  
Amino Acid Synthesis

Several regimes of supplying exogenous aromatic amino acids to intact, 3-day-old, soybean [Glycine max(L.) Merr. ‘Hill’] seedlings by root uptake were tested to determine if growth retardation caused by root-fed, 0.5 mM glyphosate [N-(phosphonomethyl) glycine] could be reversed. Generally, root-fed levels of aromatic amino acids just below growth-retarding levels (e.g. 1 mM phenylalanine + 0.1 mM tyrosine) reversed root growth inhibition caused by glyphosate to a small (ca. 10%) but significant extent. Feeding aromatic amino acids for 1 to 3 days before glyphosate exposure did not enhance the reversal. Uptake and metabolism of root-fed, aromatic amino acids in control and glyphosate-treated plants were verified by increased levels of hydroxyphenolic compounds (end products of aromatic amino acid metabolism) and by uptake and incorporation of14C-labeled phenylalanine and tyrosine. On a fresh weight basis, glyphosate had no inhibitory effect on uptake or incorporation of these amino acids into protein or secondary phenolic compounds. After 3 days of exposure, glyphosate had no substantial effects on shikimate dehydrogenase activity in control or aromatic amino acid-fed seedlings. These data suggest that either root-fed aromatic amino acids are compartmentalized differently than the endogenous pools affected by glyphosate or that root-fed glyphosate exerts most of its effect on growth of soybean seedlings through means other than inhibition of aromatic amino acid synthesis.

scholarly journals Petasis vs. Strecker Amino Acid Synthesis: Convergence, Divergence and Opportunities in Organic Synthesis

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1707
Author(s):  
Wayiza Masamba
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Organic Synthesis ◽  
Acid Synthesis ◽  
Physical Sciences ◽  
Amino Acid Synthesis

α-Amino acids find widespread applications in various areas of life and physical sciences. Their syntheses are carried out by a multitude of protocols, of which Petasis and Strecker reactions have emerged as the most straightforward and most widely used. Both reactions are three-component reactions using the same starting materials, except the nucleophilic species. The differences and similarities between these two important reactions are highlighted in this review.

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.

scholarly journals New aspects of amino acid metabolism in cancer

2019 ◽  
Vol 122 (2) ◽  
pp. 150-156 ◽  
Author(s):  
Lisa Vettore ◽  
Rebecca L. Westbrook ◽  
Daniel A. Tennant
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cancer Cells ◽  
Cancer Metabolism ◽  
Acid Synthesis ◽  
Response To Therapy ◽  
Direct Role ◽  
Amino Acid Synthesis ◽  
Metabolic Coupling ◽  
Abundant Supply

AbstractAn abundant supply of amino acids is important for cancers to sustain their proliferative drive. Alongside their direct role as substrates for protein synthesis, they can have roles in energy generation, driving the synthesis of nucleosides and maintenance of cellular redox homoeostasis. As cancer cells exist within a complex and often nutrient-poor microenvironment, they sometimes exist as part of a metabolic community, forming relationships that can be both symbiotic and parasitic. Indeed, this is particularly evident in cancers that are auxotrophic for particular amino acids. This review discusses the stromal/cancer cell relationship, by using examples to illustrate a number of different ways in which cancer cells can rely on and contribute to their microenvironment – both as a stable network and in response to therapy. In addition, it examines situations when amino acid synthesis is driven through metabolic coupling to other reactions, and synthesis is in excess of the cancer cell’s proliferative demand. Finally, it highlights the understudied area of non-proteinogenic amino acids in cancer metabolism and their potential role.

scholarly journals New Enzymatic Method of Chiral Amino Acid Synthesis by Dynamic Kinetic Resolution of Amino Acid Amides: Use of Stereoselective Amino Acid Amidases in the Presence of α-Amino-ε-Caprolactam Racemase

2007 ◽  
Vol 73 (16) ◽  
pp. 5370-5373 ◽  
Author(s):  
Shigenori Yamaguchi ◽  
Hidenobu Komeda ◽  
Yasuhisa Asano
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Kinetic Resolution ◽  
Acid Synthesis ◽  
Enzymatic Method ◽  
Ochrobactrum Anthropi ◽  
Dynamic Kinetic Resolution ◽  
Amino Acid Synthesis

ABSTRACT d- and l-amino acids were produced from l- and d-amino acid amides by d-aminopeptidase from Ochrobactrum anthropi C1-38 and l-amino acid amidase from Pseudomonas azotoformans IAM 1603, respectively, in the presence of α-amino-ε-caprolactam racemase from Achromobacter obae as the catalyst by dynamic kinetic resolution of amino acid amides.

scholarly journals Biosynthesis of Amino Acids in Xanthomonas oryzae pv. oryzae Is Essential to Its Pathogenicity

2019 ◽  
Vol 7 (12) ◽  
pp. 693 ◽  
Author(s):  
Ting Li ◽  
Zhaohong Zhan ◽  
Yunuan Lin ◽  
Maojuan Lin ◽  
Qingbiao Xie ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Bacterial Growth ◽  
Acid Synthesis ◽  
Xanthomonas Oryzae ◽  
Host Responses ◽  
Amino Acid Synthesis ◽  
Rice Bacterial Blight ◽  
Nutrient Environment ◽  
Blight Disease

Xanthomonas oryzae pv. oryzae (Xoo) is the causal agent of rice bacterial blight disease, which causes a large reduction in rice production. The successful interaction of pathogens and plants requires a particular nutrient environment that allows pathogen growth and the initiation of both pathogen and host responses. Amino acid synthesis is essential for bacterial growth when bacteria encounter amino acid-deficient environments, but the effects of amino acid synthesis on Xoo pathogenicity are unclear. Here, we systemically deleted the essential genes (leuB, leuC, leuD, ilvC, thrC, hisD, trpC, argH, metB, and aspC) involved in the synthesis of different amino acids and analyzed the effects of these mutations on Xoo virulence. Our results showed that leucine, isoleucine, valine, histidine, threonine, arginine, tryptophan, and cysteine syntheses are essential to Xoo infection. We further studied the role of leucine in the interaction between pathogens and hosts and found that leucine could stimulate some virulence-related responses and regulate Xoo pathogenicity. Our findings highlight that amino acids not only act as nutrients for bacterial growth but also play essential roles in the Xoo and rice interaction.

scholarly journals Mechanism of De Novo Branched-Chain Amino Acid Synthesis as an Alternative Electron Sink in Hypoxic Aspergillus nidulans Cells

2010 ◽  
Vol 76 (5) ◽  
pp. 1507-1515 ◽  
Author(s):  
Motoyuki Shimizu ◽  
Tatsuya Fujii ◽  
Shunsuke Masuo ◽  
Naoki Takaya
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aspergillus Nidulans ◽  
De Novo ◽  
Acid Synthesis ◽  
Branched Chain Amino Acids ◽  
Amino Acid Synthesis ◽  
Lactate Dehydrogenase Activity ◽  
Branched Chain Amino Acid ◽  
Branched Chain

ABSTRACT Although branched-chain amino acids are synthesized as building blocks of proteins, we found that the fungus Aspergillus nidulans excretes them into the culture medium under hypoxia. The transcription of predicted genes for synthesizing branched-chain amino acids was upregulated by hypoxia. A knockout strain of the gene encoding the large subunit of acetohydroxy acid synthase (AHAS), which catalyzes the initial reaction of the synthesis, required branched-chain amino acids for growth and excreted very little of them. Pyruvate, a substrate for AHAS, increased the amount of hypoxic excretion in the wild-type strain. These results indicated that the fungus responds to hypoxia by synthesizing branched-chain amino acids via a de novo mechanism. We also found that the small subunit of AHAS regulated hypoxic branched-chain amino acid production as well as cellular AHAS activity. The AHAS knockout resulted in higher ratios of NADH/NAD+ and NADPH/NADP+ under hypoxia, indicating that the branched-chain amino acid synthesis contributed to NAD+ and NADP+ regeneration. The production of branched-chain amino acids and the hypoxic induction of involved genes were partly repressed in the presence of glucose, where cells produced ethanol and lactate and increased levels of lactate dehydrogenase activity. These indicated that hypoxic branched-chain amino acid synthesis is a unique alternative mechanism that functions in the absence of glucose-to-ethanol/lactate fermentation and oxygen respiration.

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