Verbruggen I, Ladrière L, Willem R, Malaisse W J
High Resolution NMR Centre, Free University of Brussels (VUB), Belgium.
Biochem Mol Med. 1997 Aug;61(2):229-35. doi: 10.1006/bmme.1997.2604.
The generation of 13C-labeled D-glucose isotopomers by rat hepatocytes incubated for 30 or 120 min in the presence of 10 mM [3-(13)C]pyruvate was assessed by 13C NMR. The amount of C1-labeled D-glucose exceeded that of C2-labeled hexose, which was itself higher than that of C3-labeled D-glucose. A comparable hierarchy was observed in the C6-C5-C4 moiety of the hexose. The latter moiety of D-glucose was more efficiently labeled, however, than the C3-C2-C1 moiety. This finding is similar to that both previously reported and again observed in the present study when hepatocytes were exposed to [2(-13)C]pyruvate. These converging observations thus support the concept of enzyme-to-enzyme channeling of D-glyceraldehyde 3-phosphate between glyceraldehyde-3-phosphate dehydrogenase and phospho-fructoaldolase.
