C. Reynolds
Feb 1, 1980
Citations
0
Influential Citations
2
Citations
Quality indicators
Journal
Biochemical pharmacology
Abstract
Abstract Chelation by 3-aminopicolinic acid of Fe 2+ , Co 2+ and Mn 2+ has been measured spectrophotometrically. With Fe 2+ or Co 2+ , 3-aminopicolinic acid inhibited phosphoenolpyruvate carboxykinase at low metal-ion concentrations. Activation was not observed. The enzyme appears not to bind 3-aminopicolinic acid. 3-Aminopicolinic acid protects phosphoenolpyruvate carboxykinase from inactivation by ferrous ions. Two models are suggested, which could account for activation of gluconeogenesis due to chelation of metal-ions by 3-aminopicolinic acid: (a) phosphoenolpyruvate carboxykinase may be in dynamic equilibrium between inactivation by ferrous ions and reactivation by thiol compounds; and (b) metal-ions may promote product-inhibition by phosphoenolpyruvate, which chelation could alleviate.