When 4 mM 3-mercaptopicolinate, which inhibited gluconeogenesis from endogenous substrates, was included in perfusates, a continuous net uptake of unlabelled glucose was observed at all levels above 4 mM. This lowering of the null-point, cross-over glucose concentration was shown to relate ...
Mn2+ interfered with Fe2+-enhancement of inhibition by 3-mercaptopicolinate in a manner competitive with Fe2+. It is hypothesized that Fe2+ and 3-mercaptopicolinate form a coordination complex that inhibits the carboxykinases and that 3-mercaptopicolinate does not bind to a carboxykinase containing ...
The ratio of 3-mercaptopicolinate or 3-aminopicolinate to Fe2+ that caused the greatest inhibition or activation of purified phosphoenolpyruvate carboxykinase was 2:1. In the absence of Fe2+, neither pyridine carboxylate altered the activity of the enzyme. These results indicate that the two ...