ISSN:
1432-1424
Keywords:
Iron transport
;
Reticulocyt-sealed ghosts
;
Plasma membrane
;
Arginine
;
Ninhydrin
;
Phenylglyoxal
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract Sealed reticulocyte ghosts were treated with reagents that modify a variety of amino acid residues. Only ninhydrin and phenylglyoxal, both modifiers of arginyl residues, produced inhibition of the initial rate of 59Fe2+ uptake. The inhibition (i) was dependent on the concentration of ninhydrin or phenylglyoxal, (ii) increased from pH 7 to 9, a feature of the modification of arginine by ninhydrin or phenylglyoxal, and (iii) was blocked when Fe2+ was present during the modification step. A23187, an effective membrane Fe2+ transporter, diminished the inhibitory effect of ninhydrin and phenylglyoxal, indicative that the transport of iron through the membrane, and not a secondary process, was selectively inhibited. We conclude that the iron transporter from the plasma membrane of erythroid cells has one or more arginyl residues in a segment accessible to ninhydrin or phenylglyoxal, and that this residue is involved in the transmembrane transport of iron.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00235131
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