A nuclear magnetic resonance study of the role of phosphoenol pyruvate carboxykinase (PEPCK) in the glucose metabolism of Dipetalonema viteae.

13C-NMR has been applied to the study of the metabolism of [1-13C]glucose by macrofilariae of Dipetalonema viteae under conditions of restricted glucose supply. In a medium buffered with 13C-labelled bicarbonate, succinate labelled in the carboxyl position is formed in good yield. Quinolinic acid, a known inhibitor of phosphoenol pyruvate carboxykinase (PEPCK) has been shown to suppress the formation of labelled succinate from [1-13C]glucose. Both sets of experiments support the formation of succinate through the PEPCK-mediated carboxylation of phosphoenol pyruvate, followed by the operation of a partial tricarboxylic acid cycle.