Iron-binding lipids of rabbit duodenal brush-border membrane.
Rabbit duodenal brush-border membrane contains chloroform/methanol (2:1, v/v) extractable Fe-binding lipids (27.2 +/- 6.7 nmol/mg protein, mean +/- S.E. (n = 5)). Thin-layer chromatography in two solvent systems reveals that the major Fe-binding component(s) co-migrate with free fatty acids. Fe-binding by pure lipids reveals that phosphatidic acid, phosphatidylserine, oleic and stearic acids all show apparent Fe-binding in filtration assays, although oleic acid shows the highest apparent binding (5-10-fold) on a molar basis. The free fatty acid content of brush-border membrane vesicles is sufficient to account for the chloroform/methanol extractable Fe-binding observed in vesicle preparations. The pH dependence of Fe-binding by oleic acid is similar to that reported for the detergent extractable Fe-binding lipid which has been implicated in transport of Fe from Fe/ascorbate solutions by rabbit duodenal brush-border membrane vesicles (Simpson, R.J. and Peters, T.J. (1986) Biochim. Biophys. Acta 859, 227-236).
D000818:Animals; D002855:Chromatography, Thin Layer; D004386:Duodenum / Q000032:analysis*; D005227:Fatty Acids / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism*; D007504:Iron Radioisotopes; D008563:Membrane Lipids / Q000378:metabolism*; D008871:Microvilli / Q000032:analysis; D019301:Oleic Acid; D009829:Oleic Acids / Q000378:metabolism; D011817:Rabbits
D005227:Fatty Acids; D007504:Iron Radioisotopes; D008563:Membrane Lipids; D009829:Oleic Acids; D019301:Oleic Acid; D007501:Iron