Non-enzymic glycosylation of horse spleen and rat liver ferritins.

Incubation of horse spleen ferritin and rat liver ferritin with [14C]glucose, [14C]mannose or [14C]fucose resulted in the covalent incorporation of the sugar into ferritin. The rate of reaction depended on the concentrations of ferritin and sugar and time of incubation. The order of this nonenzymic incorporation was glucose greater than mannose greater than or equal to fucose. Glucosylated or mannosylated ferritin was not retained by concanavalin A. The plasma half-life of rat liver ferritin and apoferritin was found to be 20 min. This value remained unaffected by in vitro glucosylation or mannosylation of ferritin. It is suggested that varying degrees of glycosylation might account for the occurrence of isoferritins.