Pages, G., Y.L. Tan, and P.W. Kuchel, Hyperpolarized [1,(13)C]pyruvate in lysed human erythrocytes: effects of co-substrate supply on reaction time courses. NMR Biomed, 2014. 27(10): p. 1203-10.
Hyperpolarized [1,(13)C]pyruvate was injected rapidly into haemolysates in which hydrolysis of nicotinamide adenine dinucleotide (phosphate) (NAD(P))/NAD(P)H had been inhibited with nicotinamide. Haemolysates provide a stable glycolytic system in which membrane permeability is not a flux-controlling step, and they enable the concentration of NADH to be adjusted experimentally while keeping the rest of the sample with the same composition as that of the cytoplasm of the cell (albeit diluted twofold at the time of injection of the [1,(13)C]pyruvate). We showed that the maximum amplitude of the (13)C NMR signal from the [1,(13)C]L-lactate, produced from [1,(13)C]pyruvate, and the time at which it occurred was dependent on NADH concentration, as predicted by enzyme-kinetic analysis. The main feature of such curves was dictated by the immediacy of the supply of the co-substrate of lactate dehydrogenase (LDH, EC 1.1.1.27), and we posit that this also pertains in vivo in various tissues including neoplasms. By constructing an appropriate mathematical model and by using a Markov-chain Monte Carlo approach, we fitted experimental data to estimate LDH and NADH concentrations. Experiments carried out with only endogenous NADH present enabled the estimation of its effective concentration in human RBCs; the ability to make this estimate is a special feature of the rapid-dissolution dynamic nuclear polarization method. We found an endogenous NADH concentration in human RBCs two to four times higher than previously reported.
Apparent rate constant mapping using hyperpolarized [1–13C]pyruvate
From The DNP-NMR Blog:
Apparent rate constant mapping using hyperpolarized pyruvate
Khegai, O., et al., Apparent rate constant mapping using hyperpolarized pyruvate. NMR in Biomedicine, 2014. 27(10): p. 1256-1265.
http://dx.doi.org/10.1002/nbm.3174
Direct enzyme-substrate affinity determination by real-time hyperpolarized (13)C-MRS
From The DNP-NMR Blog:
Direct enzyme-substrate affinity determination by real-time hyperpolarized (13)C-MRS
Friesen-Waldner, L.J., et al., Direct enzyme-substrate affinity determination by real-time hyperpolarized (13)C-MRS. Chem Commun (Camb), 2014. 50(89): p. 13801-4.
http://www.ncbi.nlm.nih.gov/pubmed/25253534
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10-29-2014 03:51 PM
Hyperpolarized singlet lifetimes of pyruvate in human blood and in the mouse
From The DNP-NMR Blog:
Hyperpolarized singlet lifetimes of pyruvate in human blood and in the mouse
Marco-Rius, I., et al., Hyperpolarized singlet lifetimes of pyruvate in human blood and in the mouse. NMR Biomed, 2013. 26(12): p. 1696-704.
http://www.ncbi.nlm.nih.gov/pubmed/23946252
[NMR paper] Stoichiometric relationship between Na(+) ions transported and glucose consumed in human erythrocytes: Bayesian analysis of (23)Na and (13)C NMR time course data.
Stoichiometric relationship between Na(+) ions transported and glucose consumed in human erythrocytes: Bayesian analysis of (23)Na and (13)C NMR time course data.
http://www.bionmr.com//www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--linkinghub.elsevier.com-ihub-images-cellhub.gif Related Articles Stoichiometric relationship between Na(+) ions transported and glucose consumed in human erythrocytes: Bayesian analysis of (23)Na and (13)C NMR time course data.
Biophys J. 2013 Apr 16;104(8):1676-84
Authors: Puckeridge M, Chapman BE, Conigrave AD, Grieve SM,...
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10-31-2013 02:18 PM
Probing alanine transaminase catalysis with hyperpolarized 13CD3-pyruvate
From the The DNP-NMR Blog:
Probing alanine transaminase catalysis with hyperpolarized 13CD3-pyruvate
Barb, A.W., et al., Probing alanine transaminase catalysis with hyperpolarized 13CD3-pyruvate. J. Magn. Reson., 2013. 228(0): p. 59-65.
http://dx.doi.org/10.1016/j.jmr.2012.12.013