Interaction of Lactoferrin with Ceruloplasmin

• Published in: Archives of biochemistry and biophysics 2000-02, Vol.374 (2), p.222-228
• Main Authors: Zakharova, Elena T., Shavlovski, Mikhail M., Bass, Mikhail G., Gridasova, Anastasia A., Pulina, Maria O., De Filippis, Vincenzo, Beltramini, Mariano, Di Muro, Paolo, Salvato, Benedetto, Fontana, Angelo, Vasilyev, Vadim B., Gaitskhoki, Vladimir S.
• Format: Article
• Language: English
• Subjects: Animals; Apoproteins - chemistry; ceruloplasmin; Ceruloplasmin - chemistry; Ceruloplasmin - metabolism; Chromatography, Affinity; Chromatography, Gel; Electrophoresis, Polyacrylamide Gel; Female; ferroxidase; Humans; Immunoelectrophoresis; Kinetics; lactoferrin; Lactoferrin - chemistry; Lactoferrin - isolation & purification; Lactoferrin - metabolism; metalloproteins; Milk, Human - chemistry; Rats
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1006/abbi.1999.1559

When added to human blood serum, the iron-binding protein lactoferrin (LF) purified from breast milk interacts with ceruloplasmin (CP), a copper-containing oxidase. Selective binding of LF to CP is evidenced by the results of polyacrylamide gel electrophoresis, immunodiffusion, gel filtration, and affinity chromatography. The molar stoichiometry of CP:LF in the complex is 1:2. Near-uv circular dichroism spectra of the complex showed that neither of the two proteins undergoes major structural perturbations when interacting with its counterpart. Kd for the CP/LF complex was estimated from Scatchard plot as 1.8 × 10−6 M. The CP/LF complex is found in various fluids of the human body. Upon injection into rat of human LF, the latter is soon revealed within the CP/LF complex of the blood plasma, from where the human protein is substantially cleared within 5 h.