Binding of Human Serum Ferritin to Concanavalin A

Abstract

1. A high proportion of the ferritin in normal serum binds to concanavalin A. Binding is prevented by the addition of alpha-D-methylglucoside to the reaction mixture. 2. Ferritin in extracts of normal heart, liver and spleen or serum ferritin from patients with massive hepatic necrosis does not bind to concanavalin A. 3. Isoelectric focusing of preparations of serum ferritin from patients with primary haemochromatosis shows that the ferritin fraction binding to concanavalin A consists, predominantly, of the more acidic isoferritins. 4. These findings suggest that carbohydrate residues may be added to ferritin during its secretion into the plasma. Glycosylation may account for the heterogeneity of serum ferritin on isoelectric focusing. 5. Direct release of intracellular ferritin from damaged tissue may be indicated by an increase in the proportion of circulating ferritin which does not bind to concanavalin A. Such an increase has been found in sera from patients with iron overload.

A new missense mutation in the L ferritin coding sequence associated with elevated levels of glycosylated ferritin in serum and absence of iron overload

“…10 Serum was incubated for two hours at room temperature with Concanavalin A Sepharose 4B on a roller mixer. The sample was then centrifuged at 3000 rpm for 15 min and unbound ferritin was recovered in the supernatant and assayed using an immunoassay (DadeBehring).…”

EVALUATION OF SERUM FERRITIN AND SERUM IRON IN FREE-RANGING BLACK RHINOCEROS (DICEROS BICORNIS) AS A TOOL TO UNDERSTAND FACTORS AFFECTING IRON-OVERLOAD DISORDER

“…When there is tissue damage, direct release of cytosolic ferritin through damaged cell membranes becomes important. In patients with ferritinaemia resulting from necrosis of the liver, the plasma ferritin shows reduced binding to concanavalin A (67). Findings in patients with haemophagocytosis or in the early stages of haemochromatosis confirm the importance of phagocytic cells (see below).…”

“…It was suggested by Prieto et al (66) that the ratio of serum ferritin to aspartate aminotransferase activity might provide a good index of liver iron concentration. Glycosylated ferritin concentrations might be related directly to storage iron concentrations, while the concentration of non-glycosylated ferritin would relate to the degree of liver damage (67). However neither the ferritin:aspartate aminotransferase ratio (68,69) nor the measurement of glycosylated ferritin concentration (33,70) have proved to be any more reliable than the simple measurement of serum ferritin concentration as an index of liver iron concentration.…”

Increased ferritin levels in the fluid of thyroid cyst.

“…Worwood et al (1979) found that only the acidic isoferritins of human serum bound to Con A while the most basic isoferritins did not. Halliday et al (1979) reported that the plasma half-life of ferritin which was bound to Con A was approximately twice that of ferritin which did not bind.…”

“…This phenomena may be due to the fact that the most plasma proteins become glycosylated during secretion into the plasma. Such a process may be important in determining the properties of circulating ferritin (Worwood et al, 1979 …”