Amino acid metabolism in developing soybeans (Glycine max): glutamate synthase in the cotyledons

Extracts of developing soybean (Glycine max (L.) Merr.) cotyledons contained glutamate synthase activity (EC 2.6.1.53). The enzyme apparently was soluble and could be separated from glutamate dehydrogenase and NADH oxidase. Optimal synthase activity was at pH 7.8 in phosphate buffer. The enzyme was specific for L-glutamine as nitrogen donor and α-ketoglutarate as nitrogen acceptor. Activity was much greater with NADH than NADPH as reductant and evidence was obtained which indicated that the latter activity was an artifact in the in vitro assay owing to the presence of pyridine nucleotide phosphatase activity. Synthase activity was not reversible but was influenced by the addition of NAD+ to the reaction mixture. The synthesis of [14C] glutamate by crude extracts was also detected with ferredoxin as electron donor. The role of glutamate synthase in providing α-amino N for amino acid synthesis in the developing legume seed was further clarified.Glutamate dehydrogenase (EC 1.4.1.3) activity was also measured in the cotyledons and its possible role in NH4+ metabolism was discussed.

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Glutamate synthase and amino acid synthesis in higher plants

10.1016/bs.abr.2021.01.005 ◽

2021 ◽

Author(s):

Akira Suzuki

Keyword(s):

Amino Acid ◽

Higher Plants ◽

Glutamate Synthase ◽

Acid Synthesis ◽

Amino Acid Synthesis

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

Weed Science ◽

10.1017/s0043174500061993 ◽

1981 ◽

Vol 29 (3) ◽

pp. 297-302 ◽

Cited By ~ 10

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.

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Studies on the function of proplastids in the metabolism of in vitro-cultured tobacco cells III. Source of reducing power for amino acid synthesis from nitrite

Plant and Cell Physiology ◽

10.1093/oxfordjournals.pcp.a075545 ◽

1977 ◽

Vol 18 (6) ◽

pp. 1235-1241 ◽

Cited By ~ 13

Author(s):

Izumi Washitani ◽

Sitiro Sato

Keyword(s):

Amino Acid ◽

Reducing Power ◽

Acid Synthesis ◽

Amino Acid Synthesis ◽

Tobacco Cells

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Faculty Opinions recommendation of Photoredox activation of carbon dioxide for amino acid synthesis in continuous flow.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.727212076.793527478 ◽

2017 ◽

Author(s):

Donald Pinto ◽

Kumar Pabbisetty ◽

Vladimir Ladziata

Keyword(s):

Carbon Dioxide ◽

Amino Acid ◽

Continuous Flow ◽

Acid Synthesis ◽

Amino Acid Synthesis

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

Molecules ◽

10.3390/molecules26061707 ◽

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.

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Specificity of the HIV-1 Protease on Substrates Representing the Cleavage Site in the Proximal Zinc-Finger of HIV-1 Nucleocapsid Protein

Viruses ◽

10.3390/v13061092 ◽

2021 ◽

Vol 13 (6) ◽

pp. 1092

Author(s):

János András Mótyán ◽

Márió Miczi ◽

Stephen Oroszlan ◽

József Tőzsér

Keyword(s):

Amino Acid ◽

Zinc Finger ◽

Cleavage Site ◽

Potential Role ◽

Binding Mode ◽

Interaction Energies ◽

Vitro Assay ◽

Hiv 1

To explore the sequence context-dependent nature of the human immunodeficiency virus type 1 (HIV-1) protease’s specificity and to provide a rationale for viral mutagenesis to study the potential role of the nucleocapsid (NC) processing in HIV-1 replication, synthetic oligopeptide substrates representing the wild-type and modified versions of the proximal cleavage site of HIV-1 NC were assayed as substrates of the HIV-1 protease (PR). The S1′ substrate binding site of HIV-1 PR was studied by an in vitro assay using KIVKCF↓NCGK decapeptides having amino acid substitutions of N17 residue of the cleavage site of the first zinc-finger domain, and in silico calculations were also performed to investigate amino acid preferences of S1′ site. Second site substitutions have also been designed to produce “revertant” substrates and convert a non-hydrolysable sequence (having glycine in place of N17) to a substrate. The specificity constants obtained for peptides containing non-charged P1′ substitutions correlated well with the residue volume, while the correlation with the calculated interaction energies showed the importance of hydrophobicity: interaction energies with polar residues were related to substantially lower specificity constants. Cleavable “revertants” showed one residue shift of cleavage position due to an alternative productive binding mode, and surprisingly, a double cleavage of a substrate was also observed. The results revealed the importance of alternative binding possibilities of substrates into the HIV-1 PR. The introduction of the “revertant” mutations into infectious virus clones may provide further insights into the potential role of NC processing in the early phase of the viral life-cycle.

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