Measurement of 2H distribution in natural products by quantitative 2H NMR: An approach to understanding metabolism and enzyme mechanism?

Robins, Richard J.; Billault, Isabelle; Duan, Jia-Rong; Guiet, Sébastien; Pionnier, Sébastien; Zhang, Ben‐Li

doi:10.1023/b:phyt.0000004301.52646.a8

Cited by 45 publications

(32 citation statements)

References 46 publications

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“…From Equations 5 and 6 it can be concluded that hydrogen is introduced into the CH 3 or CH 2 OH of ethanol from the medium to a very similar extent. However, it is also clear from the residues that the contribution of the non-exchangeable sites in glucose is greater for the CH 2 OH than for the CH 3 Table 1 show that the redistribution of 2 H from glucose to ethanol is site-specific and varies with the position j of the substrate. Equations 9 -15 are the solutions to Equation 1 for the fermentation of glucose slightly deuterated at the 1, 2, or 3 positions in the presence of natural abundance water.…”

Section: Resultsmentioning

confidence: 95%

“…The value of these parameters is principally defined by the exchange reactions that can occur, directly or indirectly, between the water of the medium and the hydrogen atoms in the substrate, the intermediates and the products, and the kinetic isotope effects associated with the biochemical reactions involved in the fermentation pathway. These influences lead to a non-statistical distribution of 2 H in the population of monodeuterated isotopomers within the final product (3).…”

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confidence: 99%

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Non-equivalence of Hydrogen Transfer from Glucose to the pro-R and pro-S Methylene Positions of Ethanol during Fermentation by Leuconostoc mesenteroides Quantified by 2H NMR at Natural Abundance

Robins

Petavy

Nemmaoui

et al. 2008

Journal of Biological Chemistry

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The anaerobic fermentation of glucose by Leuconostoc mesenteroides via the reductive pentose phosphate pathway leads to the accumulation of lactic acid and ethanol. The isotope redistribution coefficients (a ij ) that characterize the specific derivation of each hydrogen atom in ethanol in relation to the non-exchangeable hydrogen atoms in glucose and the medium water have been determined using quantitative 2 H NMR. First, it is confirmed that the hydrogens of the methylene group are related only to the 1 and 3 positions of glucose via the NAD(P)H pool and not to the 4 position, in contrast to ethanol produced by Saccharomyces cerevisiae. Second, it is found that the conversion factors (C f ) for the transfer of hydrogen to the pro-S and pro-R positions of the methylene group are not equivalent: the C f -1-R:C f -1-S ratio is 2.1, whereas the C f -3-R:C f -3-S ratio is 0.8. It is shown that this non-equivalence is not determined by the stereochemistry of the terminal NADH-and NADPH-dependent alcohol dehydrogenases, but is dependent on the cofactor selectivities of the reductive and oxidative steps of the reduced nucleotide cycle.

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Section: Resultsmentioning

confidence: 95%

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confidence: 99%

Non-equivalence of Hydrogen Transfer from Glucose to the pro-R and pro-S Methylene Positions of Ethanol during Fermentation by Leuconostoc mesenteroides Quantified by 2H NMR at Natural Abundance

Robins

Petavy

Nemmaoui

et al. 2008

Journal of Biological Chemistry

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“…Isotopic labeling studies of fatty acid biosynthesis in vitro provide a rough accounting of the H sources for fatty acids (1,35,36). They indicate that the most important cellular H source is NAD(P)H, providing Ϸ50% of fatty acid H (Fig.…”

Section: Sources Of D/h Variability In Fatty Acidsmentioning

confidence: 99%

“…These were in turn calibrated against the VSMOW, GISP, and SLAP international standards (60). Average precision was 0.7‰ (1). ␦D values of nonexchangeable H in selected organic substrates were analyzed by Dr. A. Schimmelmann (Indiana University, Bloomington) by double-equilibration following the description in SI Methods.…”

Section: Isotopic Analysesmentioning

confidence: 99%

“…T he hydrogen-isotopic composition ( 2 H/ 1 H or D/H ratio, commonly expressed as a ␦D value) of lipids is being explored by scientists with diverse interests, including the origins of natural products (1,2), biogeochemical cycles (3), petroleum systems (4), and paleoclimate (5-7). Because the D/H ratios of lipids are generally conserved over Ϸ10 6 -year time scales (8), they are a potentially useful tracer of biogeochemical pathways and processes in the environment.…”

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Large D/H variations in bacterial lipids reflect central metabolic pathways

Zhang¹,

Gillespie

Sessions

2009

Proc. Natl. Acad. Sci. U.S.A.

195

268

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Large hydrogen-isotopic (D/H) fractionations between lipids and growth water have been observed in most organisms studied to date. These fractionations are generally attributed to isotope effects in the biosynthesis of lipids, and are frequently assumed to be approximately constant for the purpose of reconstructing climatic variables. Here, we report D/H fractionations between lipids and water in 4 cultured members of the phylum Proteobacteria, and show that they can vary by up to 500‰ in a single organism. The variation cannot be attributed to lipid biosynthesis as there is no significant change in these pathways between cultures, nor can it be attributed to changing substrate D/H ratios. More importantly, lipid/water D/H fractionations vary systematically with metabolism: chemoautotrophic growth (approximately ؊200 to ؊400‰), photoautotrophic growth (؊150 to ؊250‰), heterotrophic growth on sugars (0 to ؊150‰), and heterotrophic growth on TCA-cycle precursors and intermediates (؊50 to ؉200‰) all yield different fractionations. We hypothesize that the D/H ratios of lipids are controlled largely by those of NADPH used for biosynthesis, rather than by isotope effects within the lipid biosynthetic pathway itself. Our results suggest that different central metabolic pathways yield NADPH-and indirectly lipids-with characteristic isotopic compositions. If so, lipid ␦D values could become an important biogeochemical tool for linking lipids to energy metabolism, and would yield information that is highly complementary to that provided by 13 C about pathways of carbon fixation.fatty acids ͉ fractionation ͉ metabolism ͉ hydrogen isotopes T he hydrogen-isotopic composition ( 2 H/ 1 H or D/H ratio, commonly expressed as a ␦D value) of lipids is being explored by scientists with diverse interests, including the origins of natural products (1, 2), biogeochemical cycles (3), petroleum systems (4), and paleoclimate (5-7). Because the D/H ratios of lipids are generally conserved over Ϸ10 6 -year time scales (8), they are a potentially useful tracer of biogeochemical pathways and processes in the environment. Most research to date has focused on higher plants, in which environmental water is the sole source of external hydrogen and consequently provides primary control over the D/H ratio of biosynthesized lipids (9). Although ␦D values for plant lipids and environmental water are generally well correlated, they are also substantially offset from each other. The biochemical basis for this lipid/water fractionation is not well understood. It is generally assumed to arise from a combination of isotope effects during photosynthesis and the biosynthesis of lipids (9-12), and is often treated as approximately constant to reconstruct isotopic compositions of environmental water as a paleoclimate proxy.There is, however, mounting evidence that the net D/H fractionation between lipids and water can vary by up to 150‰ in plants, even in the same organism (12-16). Modest fractionations associated with fatty acid elongation and desaturation ...

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Analysis of NAD 2D‐NMR Spectra of Saturated Fatty Acids in Polypeptide Aligning Media by Experimental and Modeling Approaches

Serhan

Borgogno

Billault

et al. 2011

Chemistry A European J

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The overall and detailed elucidation (including the stereochemical aspects) of enzymatic mechanisms requires the access to all reliable information related to the natural isotopic fractionation of both precursors and products. Natural abundance deuterium (NAD) 2D-NMR experiments in polypeptide liquid-crystalline solutions are a new, suitable tool for analyzing site-specific deuterium isotopic distribution profiles. Here this method is utilized for analyzing saturated C14 to C18 fatty acid methyl esters (FAMEs), which are challenging because of the crowding of signals in a narrow spectral region. Experiments in achiral and chiral oriented solutions were performed. The spectral analysis is supplemented by the theoretical prediction of quadrupolar splittings as a function of the geometry and flexibility of FAMEs, based on a novel computational methodology. This allows us to confirm the spectral assignments, while providing insights into the mechanism of solute ordering in liquid-crystalline polypeptide solutions. This is found to be dominated by steric repulsions between FAMEs and polypeptides.

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Measurement of 2H distribution in natural products by quantitative 2H NMR: An approach to understanding metabolism and enzyme mechanism?

Cited by 45 publications

References 46 publications

Non-equivalence of Hydrogen Transfer from Glucose to the pro-R and pro-S Methylene Positions of Ethanol during Fermentation by Leuconostoc mesenteroides Quantified by 2H NMR at Natural Abundance

Non-equivalence of Hydrogen Transfer from Glucose to the pro-R and pro-S Methylene Positions of Ethanol during Fermentation by Leuconostoc mesenteroides Quantified by 2H NMR at Natural Abundance

Large D/H variations in bacterial lipids reflect central metabolic pathways

Analysis of NAD 2D‐NMR Spectra of Saturated Fatty Acids in Polypeptide Aligning Media by Experimental and Modeling Approaches

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