Interaction of lactoferrin with ceruloplasmin.
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. K(d) for the CP/LF complex was estimated from Scatchard plot as 1.8 x 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.
Zakharova
E T
ET
Institute for Experimental Medicine, St. Petersburg, Russia.
Shavlovski
M M
MM
Bass
M G
MG
Gridasova
A A
AA
Pulina
M O
MO
De Filippis
V
V
Beltramini
M
M
Di Muro
P
P
Salvato
B
B
Fontana
A
A
Vasilyev
V B
VB
Gaitskhoki
V S
VS
D000818:Animals; D001059:Apoproteins / Q000737:chemistry; D002570:Ceruloplasmin / Q000737:chemistry* / Q000378:metabolism; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007122:Immunoelectrophoresis; D007700:Kinetics; D007781:Lactoferrin / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D008895:Milk, Human / Q000737:chemistry; D051381:Rats
D001059:Apoproteins; D002570:Ceruloplasmin; D007781:Lactoferrin