- The Biosynthesis of Showdomycin: Studies with Stable Isotopes and the Determination of Principal Precursors
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Studies with stable isotopes show that D-ribose and L-glutamic acid are direct biosynthetic precursors of showdomycin (1), with carbons 2-5 and the nitrogen of L-glutamate giving rise to the maleimide ring: L-pyroglutamate may be an intermediate.
- Buchanan, J. Grant,Hamblin, Michael R.,Kumar, Ajit,Wightman, Richard H.
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- LYSINE ISOTOPOLOGUES, COMPOSITIONS COMPRISING THE SAME AND METHODS OF SYNTHESIS
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This invention relates to lysine isotopologues of Formulas I and 1-A, as described herein, and processes for synthesizing the same and derivatives and intermediates involved therein. In one aspect, described herein is a chemical compound comprising an isotopically labeled analog, i.e., an isotopologue of a standard or naturally occurring lysine. The lysine isotopologue is synthetically formed to have stable isotopes of elements incorporated at selected positions. As such, the lysine isotopologue has a molecular mass different from the mass of a standard or naturally occurring lysine.
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Paragraph 0152-0158
(2016/02/12)
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- Specific detection of cellular glutamine hydrolysis in live cells using HNCO triple resonance NMR
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Glutamine plays key roles as a biosynthetic precursor or an energy source in cancers, and interest in its metabolism is rapidly growing. However, the proper evaluation of glutamine hydrolysis, the very first reaction in the entire glutaminolysis, has been difficult. Here, we report a triple resonance NMR-based assay for specific detection of glutaminase activity carrying out this reaction using stable-isotope labeled glutamine. Compared to conventional methods involving coupled enzyme assays, the proposed approach is direct because it detects the presence of the H-N-CO amide spin system. In addition, the method is unique in enabling the measurement of glutamine hydrolysis reaction in real-time in live cells. The approach was applied to investigating the effects of a glutaminase inhibitor and the inhibitory effects of glucose on glutamine metabolism in live cells. It can be easily applied to studying other signals that affect cellular glutamine metabolism.
- Lee, Sujin,Wen, He,Cha, Jin Wook,Park, Sunghyouk
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p. 3140 - 3145
(2016/11/29)
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- Synthesis of stereoarray isotope labeled (SAIL) lysine via the "head-to-tail" conversion of SAIL glutamic acid
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A stereoarray isotope labeled (SAIL) lysine, (2S,3R,4R,5S,6R)-[3,4,5,6- 2H4;1,2,3,4,5,6-13C6;2,6- 15N2]lysine, was synthesized by the "head-to- tail" conversion of SAIL-Glu, (2S,3S,4R)-[3,4-2H 2;1,2,3,4,5-13C5;2-15N]glutamic acid, with high stereospecificities for all five chiral centers. With the SAIL-Lys in hand, the unambiguous simultaneous stereospecific assignments were able to be established for each of the prochiral protons within the four methylene groups of the Lys side chains in proteins.
- Terauchi, Tsutomu,Kamikawai, Tomoe,Vinogradov, Maxim G.,Starodubtseva, Eugenia V.,Takeda, Mitsuhiro,Kainosho, Masatsune
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supporting information; experimental part
p. 161 - 163
(2011/03/20)
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- Carbapenem biosynthesis: Confirmation of stereochemical assignments and the role of CarC in the ring stereoinversion process from L-Proline
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(5R)-Carbapen-2-em-3-carboxylic acid is the simplest structurally among the naturally occurring carbapenem β-lactam antibiotics. It co-occurs with two saturated (3S,5S)- and (3S,5R)-carbapenam carboxylic acids. Confusion persists in the literature about t
- Stapon, Anthony,Li, Rongfeng,Townsend, Craig A.
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p. 8486 - 8493
(2007/10/03)
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- Chemo-enzymatic synthesis of specifically stable-isotope labelled L-glutamic acid and 2-oxoglutaric acid
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(3-13C)-(4-13C)-,(5-13C)- and (3,4-13C2)-2-oxoglutaric acid were prepared starting from the simple 13C-enriched compounds: ethyl bromoacetate and paraformaldehyde, via a single reaction scheme on the gram scale in high yield.This reaction scheme allows specific 13C enrichment of every carbon position and any combination of positions. (3-13C)-,(4-13C)-, (5-13C), (3,4-13C2) and (15N)-L-glutamic acid were prepared by converting the corresponding 2-oxoglutaric acids via an enantioselective enzymatic conversion.The labelled L-glutamic acids and 2-oxoglutaric acids were characterized by 1H NMR, 13C NMR and mass spectrometry.
- Cappon, J. J.,Baart, J.,Walle, G. A. M. van der,Raap, J.,Lugtenburg, J.
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p. 158 - 166
(2007/10/02)
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