Alternate iron transport pathway. Mobilferrin and integrin in K562 cells.

Conrad, Marcel E.; Umbreit, Jay N.; Moore, Elizabeth; Uzel, Connie; Berry, Michael

doi:10.1016/s0021-9258(17)37263-0

Cited by 49 publications

(3 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Iron uptake was measured by adding 10 -8 M iron-59 citrate (150 000 cpm/well) and incubating for various intervals. The iron citrate chelate effectively solubilized the ferric iron and permitted uptake by the alternate pathway of iron absorption as previously described (Conrad et al, 1994). Macromolecular complexes of ferric hydroxides (Spiro & Saltman, 1967) were not present as demonstrated by the failure of radioactivity to be sedimented by ultracentrifugation (134000g for 3 h).…”

Section: Methodsmentioning

confidence: 75%

“…Antibodies. Polyclonal antibodies were raised in rabbits using purified isolates of mobilferrin (Conrad et al, 1990a); these reacted with both isolated and recombinant calreticulin (Conrad et al, 1993b(Conrad et al, , 1994. Polyclonal antibodies against integrins were raised in rabbits using isolations of rat integrin extracted from the 150 kDa protein bands on SDS-PAGE gels .…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Paraferritin: A Protein Complex with Ferrireductase Activity Is Associated with Iron Absorption in Rats

et al. 1996

View full text Add to dashboard Cite

Recent studies reported that iron salts were absorbed in the duodenum utilizing a pathway involving membrane-associated integrin and a cytosolic protein named mobilferrin. In addition, a large molecular weight cytoplasmic complex was labeled with radioiron during mucosal uptake of iron in the duodenum. The molecular mass of this protein was 520 000 daltons, slightly larger than ferritin. On denaturing SDS-PAGE, the purified protein complex appeared to consist of at least four polypeptides, closely associated with each other. This complex was called paraferritin because its hydrodynamic volume resembled ferritin. In the present work, antibody studies demonstrate the presence of integrin, mobilferrin, and flavin monooxygenase in the water-soluble complex. Biochemical studies demonstrate the presence of a NADPH-dependent flavin monooxygenase ferrireductase activity that reduces Fe(III) to Fe(II). Antibodies against either integrin or mobilferrin inhibit monooxygenase activity. Inhibition of monooxygenase activity decreases radioiron uptake by tissue culture intestinal cells. Thus, we postulated that paraferritin plays a role in the mucosal uptake and transport of inorganic iron in small intestinal absorptive cells and is a mechanism for both the internalization of integrin from membranes to cellular cytosol and the delivery of iron to cellular constituents in an appropriate redox state.

show abstract

Section: Methodsmentioning

confidence: 75%

Section: Methodsmentioning

confidence: 99%

Paraferritin: A Protein Complex with Ferrireductase Activity Is Associated with Iron Absorption in Rats

et al. 1996

View full text Add to dashboard Cite

show abstract

“…These considerations, taken together with the results illustrated in Figure 2, may favor the idea of a potential therapeutic use of the ironpeptide complex. In vitro experiments have suggested some processes of inorganic iron uptake, among them electrogenic Fe(III) transport (34), the formation of Fe(II) complexes with free fatty acids facilitating their transfer through the membranes (35), Fe(III) binding to membrane proteins such as glycoproteins (36), integrins (37), melanotransferrin (38), or major histocompatibity class I molecules (39), in addition to paracellular absorption (26). There still is no conclusive evidence that might permit us to state that iron is taken up in the II or III form (26,40), although the activity of ferrireductases involved in the process of iron absorption (26,40) or in cytoplasmic transit (30) has been reported.…”

Section: Discussionmentioning

confidence: 99%

Iron Derivatives from Casein Hydrolysates as a Potential Source in the Treatment of Iron Deficiency

Chaud

Izumi

Nahaal

et al. 2002

J. Agric. Food Chem.

131

109

View full text Add to dashboard Cite

The properties of an Fe(3+)-peptide complex containing 5.6% Fe, obtained by the reaction of ferric chloride with an enzymatic hydrolysate of casein, are described. The major site of iron binding corresponds primarily to the carboxylate groups and to a lesser extent to the peptide bonds. The Fe(3+)-peptide complex is insoluble at acid pH and completely soluble at neutral to alkaline pH. When soluble, the Fe(3+) is tightly bound to the complex peptide mixture but can be displaced and complexed by a low molecular weight ligand such as cysteine. Its efficacy in relation to iron sulfate was compared in rats. Both iron sources were administrated in Milli-Q water by gastric gavage to male Wistar rats (180-200 g) after an 18 h fast with water ad libitum. Fe(3+) from the Fe(3+)-peptide complex was transferred to the blood in a dose-dependent manner (1-8 mg of Fe/kg), and the serum iron levels were significantly higher (p < 0.001) than in a similar group of rats treated with iron sulfate. In the comparative kinetics experiments, the rats received 4 mg of Fe/kg. Both iron sources presented maximum absorption, as indicated by the elevation of serum iron levels, 30 min after administration, and the AUC(0)(-->2h) of the Fe(3+)-peptide complex was significantly higher (p < 0.05) than that observed with iron sulfate. The simultaneous administration of free peptides (0-192 mg) with the Fe(3+)-peptide complex or iron sulfate did not modify the extent of absorption of iron from both sources, suggesting that the absorption is due to the complex formed and probably not to exchange reactions in the gastrointestinal tract. In the hemoglobin repletion experiments carried out on newly weaned rats with anemia induced by a low-iron diet, supplementation of the diet with the the Fe(3+)-peptide complex was as efficient as supplementation with iron sulfate in the conversion from diet to hemoglobin iron. These results, taken together, suggest that the Fe(3+)-peptide complex is a potential compound for use as an iron source in biological situations.

show abstract

Integrin beta3 Blockade With Abciximab and Protection From Myocardial Ischemic Events

Conrad¹,

Umbreit²,

Moore³

1998

JAMA: The Journal of the American Medical Association

View full text Add to dashboard Cite

Alternate iron transport pathway. Mobilferrin and integrin in K562 cells.

Cited by 49 publications

References 29 publications

Paraferritin: A Protein Complex with Ferrireductase Activity Is Associated with Iron Absorption in Rats

Paraferritin: A Protein Complex with Ferrireductase Activity Is Associated with Iron Absorption in Rats

Iron Derivatives from Casein Hydrolysates as a Potential Source in the Treatment of Iron Deficiency

Integrin beta3 Blockade With Abciximab and Protection From Myocardial Ischemic Events

Contact Info

Product

Resources

About