In vitro interaction between ceruloplasmin and human serum transferrin.
The thermodynamics of the interactions of serum apotransferrin (T) and holotransferrin (TFe(2)) with ceruloplasmin (Cp), as well as those of human lactoferrin (Lf), were assessed by fluorescence emission spectroscopy. Cp interacts with two Lf molecules. The first interaction depends on pH and μ, whereas the second does not. Dissociation constants were as follows: K(11Lf) = 1.5 ± 0.2 μM, and K(12Lf) = 11 ± 2 μM. Two slightly different interactions of T or TFe(2) with Cp are detected for the first time. They are both independent of pH and μ and occur with 1:1 stoichiometry: K(1T) = 19 ± 7 μM, and K(1TFe2) = 12 ± 4 μM. These results can improve our understanding of the probable process of the transfer of iron from Cp to T in iron and copper transport and homeostasis.
Laboratoire ITODYS (Interfaces, Traitements et Organisation des Systèmes), Université Paris-Diderot, CNRS UMR 7086, Bâtiment Lavoisier, 15 rue Jean-Antoine de Baïf, Paris Cedex 13, France. thanh.haduong@univ-paris-diderot.fr
Nguyêt-Thanh
NT
Ha-Duong
Chantal
C
Eid
Miryana
M
Hémadi
Jean-Michel
JM
El Hage Chahine
D001059:Apoproteins / Q000378:metabolism; D002570:Ceruloplasmin / Q000378:metabolism*; D006801:Humans; D007781:Lactoferrin / Q000378:metabolism; D011485:Protein Binding; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics; D014168:Transferrin / Q000378:metabolism*
D001059:Apoproteins; D014168:Transferrin; C028284:apotransferrin; C110714:holotransferrin; D002570:Ceruloplasmin; D007781:Lactoferrin