SYNOPSIS A method is described for measuring the plasma unsaturated iron-binding capacity in the presence of very high concentrations of iron as iron-dextran. The procedure utilizes 59Fe to label the apotransferrin with subsequent separation of ionic iron from transferrin-bound iron on an ion exchange or Sephadex G.25 column. The unsaturated iron-binding capacity has been measured in rabbits an...

HeLa cells were found to have a single class of non-interacting receptors specific for transferrin. Both apotransferrin and diferric transferrin competed equally with 125I-diferric transferrin for receptor binding. Transferrin binding was temperature-dependent and reversible. Binding of transferrin to cells exhibited a KD of 27 nM with a maximum binding capacity of 1.8-3.7 x 10(6) molecules/cel...

The potential roles of vesicular transport and apotransferrin (entering from the blood) in intestinal Fe absorption were investigated using Caco-2 cell monolayers with tight junctions in bicameral chambers as a model. As shown previously, addition of 39 microM apotransferrin (apoTf) to the basolateral fluid during absorption studies markedly stimulated overall transport of 1 microM (59)Fe from ...

In the present study, the relationship among iron-availability, antibacterial activity, role of meconium as an iron source and the activity of bacterial iron-uptake system (IUS) for bacterial growth in amniotic fluid (AF) were investigated. Staphylococcus aureus ATCC 6538 and its streptonigrin-resistant (SR) mutant with defective IUS were used as the test strains. The growth of S. aureus in AF ...

The interaction of two antitumor ruthenium(III) complexes,-Na[trans-RuCl(4)(DMSO)(Im)] and Na[trans-RuCl(4)(DMSO)(Ind)]- with human serum apotransferrin (apoTf) was investigated through a number of spectroscopic techniques such as UV-Vis absorption, CD and (1)H NMR spectroscopy. Interestingly, the hydrolysis profiles of these complexes in a physiological buffer are markedly affected by the pres...

1. Both albumin and transferrin have been suggested as carriers of zinc in plasma. Their relative importance in Zn transport was therefore investigated as a preliminary to a study of the rates of passage of Zn through plasma. 2. The apparent log stability constant for Zn binding to human apotransferrin at pH 7.4 was estimated to be approximately 5.9 which is substantially lower than previous re...

Polyacrylamide-gel electrophoresis in urea was used to prepare the four molecular species of transferrin:diferric transferrin, apotransferrin and the two monoferric transferrins with either the C-terminal or the N-terminal metal-binding site occupied. The interaction of these 1251-labelled proteins with rabbit reticulocytes was investigated. At 4°C the average value for the association constant...

A method is described for measuring the plasma unsaturated iron-binding capacity in the presence of very high concentrations of iron as iron-dextran. The procedure utilizes (59)Fe to label the apotransferrin with subsequent separation of ionic iron from transferrin-bound iron on an ion exchange or Sephadex G.25 column. The unsaturated iron-binding capacity has been measured in rabbits and dogs ...