Recombinant human lactoferrin and iron transport across Caco-2 monolayers: effect of heat treatment on the binding to cells.
Recombinant human lactoferrin (rhLF) from Aspergillus awamori bound to Caco-2 cell membranes in a saturable manner. The dissociation constant for the apo form was (Kd)=2.2 x 10(-7) M; however, the specific binding of the iron-saturated rhLF and of lactoferrin from human milk (hLF) was too low to calculate the binding parameters. Recombinant human lactoferrin subjected to heat treatment did not lose the ability to bind to cell membranes except at high temperature and long time treatments (85 and 89 degrees C for 40 min) for which there was a slight decrease in the binding. No significant differences have been found in the transport of iron bound to rhLF or to hLF across Caco-2 cell monolayers. Nevertheless, the amount of iron-saturated hLF transported across Caco-2 monolayers was significantly higher than that of rhLF. For both lactoferrins, the amount of intact protein in the lower chamber was about 4.5% of the total radioactivity transported, indicating the degradation of lactoferrin in the passage across Caco-2 cells.
Conesa
Celia
C
Tecnología de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain.
Pocoví
Coloma
C
Pérez
María-Dolores
MD
Calvo
Miguel
M
Sánchez
Lourdes
L
D001667:Binding, Competitive; D001692:Biological Transport; D018938:Caco-2 Cells; D002462:Cell Membrane / Q000378:metabolism*; D006358:Hot Temperature; D006801:Humans; D007501:Iron / Q000378:metabolism*; D007781:Lactoferrin / Q000378:metabolism*; D008895:Milk, Human / Q000737:chemistry; D011994:Recombinant Proteins / Q000378:metabolism
D011994:Recombinant Proteins; D007501:Iron; D007781:Lactoferrin