13C NMR study of C2- and C3-deuterated lactic acid production by parotid cells exposed to 13C-labeled glucose in the presence of D2O.
The generation of C2- and C3-deuterated lactic acid produced by rat parotid cells exposed to [1-13C] glucose, [2-13C]glucose, and [6-13C]glucose in the presence of D2O was assessed by 13C NMR. The results indicated that the escape from deuteration amounted to about 46% at the phosphoglucoisomerase level, 100% at the phosphomannoisomerase level, 65% in the reactions catalyzed by phosphofructoaldolase and triose phosphate isomerase, and 58% at the level of glutamate pyruvate transaminase. Such high values are considered to support a possible enzyme-to-enzyme tunneling of metabolic intermediates at selected sites in the glycolytic pathway.
Malaisse
W J
WJ
Laboratory of Experimental Medicine, Université Libre de Bruxelles (ULB), Belgium.
Biesemans
M
M
Sener
A
A
Willem
R
R
D000818:Animals; D002247:Carbon Isotopes; D003903:Deuterium; D005260:Female; D005947:Glucose / Q000494:pharmacology*; D007773:Lactates / Q000096:biosynthesis*; D019344:Lactic Acid; D009682:Magnetic Resonance Spectroscopy; D008433:Mathematics; D010306:Parotid Gland / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051381:Rats
D002247:Carbon Isotopes; D007773:Lactates; D019344:Lactic Acid; D003903:Deuterium; D005947:Glucose