- Tytuł:
- Multiple isotope effects as a probe of the tartrate dehydrogenase-catalyzed oxidative decarboxylation of D-malate
- Autorzy:
-
Karsten, W.
Cook, P. - Powiązania:
- https://bibliotekanauki.pl/articles/147116.pdf
- Data publikacji:
- 2002
- Wydawca:
- Instytut Chemii i Techniki Jądrowej
- Tematy:
-
isotope effects
malic enzyme
oxidative decarboxylation
tartrate dehydrogenase - Opis:
- A change in the dinucleotide reactant from NAD+ to the more oxidizing APAD+ in the malic enzyme reaction results in a change in the mechanism of oxidative decarboxylation of malate from stepwise to concerted [7]. In order to determine whether this is a phenomenon general to metal ion dependent â-hydroxyacid oxidative decarboxylases, tartrate dehydrogenase, which catalyzes a reaction diastereotopic to malic enzyme, was studied using the technique of multiple isotope effects. A primary deuterium isotope effect of 1.41 on V/Kmalate was measured, as well as a primary 13C-isotope effect of 1.0096. A decrease in the measured value of the 13C-isotope effect to 1.0078 is consistent with a stepwise mechanism, as observed for malic enzyme. The 13C-isotope effect with thioNAD+ also decreases from a value of 1.0053 using D-malate to 1.0009 using D-malate-2-D, consistent with stepwise oxidative decarboxylation with this alternative dinucleotide substrate. The data suggest that the change
- Źródło:
-
Nukleonika; 2002, 47,suppl.1; 13-15
0029-5922
1508-5791 - Pojawia się w:
- Nukleonika
- Dostawca treści:
- Biblioteka Nauki
Artykuł