RESUMEN
Interaction between 6-mercaptopurine, Cu2+ and the enzyme xanthine oxidase (EC 1.2.3.2.) was examined. Whereas Cu2+ was found to inhibit the enzyme, 6-mercaptopurine could protect as well as reverse the enzyme inhibition produced by the metal ion. The formation of a complex between 6-mercaptopurine and Cu2+ seems to be responsible for the observed effect. Job's [(1928) Ann. Chem. 9, 113] method has shown the composition of the complex to be 1:1. The apparent stability constant (log K value), as determined by Subhrama Rao & Raghav Rao's [(1955) J. Sci. Chem. Ind. Res. 143, 278], method is found to be 6.74. It is suggested that the formation of a stable complex between 6-mercaptopurine molecules and Cu2+ may be an additional mechanism of action of 6-mercaptopurine, particularly with reference to its anti-inflammatory properties.
Asunto(s)
Cobre/metabolismo , Mercaptopurina/farmacología , Xantina Oxidasa/metabolismo , Sustancias Macromoleculares , Espectrofotometría , Xantina Oxidasa/antagonistas & inhibidoresAsunto(s)
Xantina Oxidasa/antagonistas & inhibidores , Xantinas/farmacología , Animales , Encéfalo/enzimología , Búfalos , Cafeína/farmacología , Femenino , Técnicas In Vitro , Riñón/enzimología , Cinética , Pulmón/enzimología , Leche/enzimología , Miocardio/enzimología , Ratas , Teobromina/farmacología , Teofilina/farmacología , Ácido Úrico/metabolismoRESUMEN
L-Glutamic acid has been found to be a positive and L-lysine a negative modifier of the xanthine oxidase activity at the optimum pH (7.4) of the enzyme. Increase in pH was observed to be associated with a progressive decrease in the inhibition produced by L-lysine.