Characterization of ferritin and ferritin-binding proteins in canine serum.
Ferritin and ferritin-binding proteins in canine serum were characterized. A certain percentage of ferritin in canine serum, but no tissue ferritin, was precipitated by centrifugation at 16,000 x g for 30 min. The precipitated ferritin was found to contain two subunits corresponding to the H and L subunits of canine liver ferritin by immunoblotting, the H subunit being predominant. More ferritin was precipitated from canine sera which had been incubated with anti-rat liver ferritin antibody than from untreated sera, and the H chain also predominated. To evaluate the possibility that the autoantibody was responsible for the precipitation of canine serum ferritin, the ferritin-binding activities of canine antibodies were examined using liver ferritin-coated microtiter plates and alkaline phosphatase-labeled antibodies specific for canine IgM, IgA, and IgG heavy chains. The results showed that IgM and IgA, but not IgG, had considerable ferritin-binding activities. Given these results, we suggest that there is H-chain-rich isoferritin in canine serum, and that ferritin exists as an immune complex.
Watanabe
K
K
Laboratory of Biochemistry, School of Veterinary Medicine and Animal Sciences, Kitasato University, Towada, Japan. watanabe@vmas.kitasato-u.ac.jp
Hayashi
K
K
Miyamoto
T
T
Tanaka
M
M
Okano
S
S
Yamamoto
S
S
D000818:Animals; D000936:Antigen-Antibody Complex / Q000097:blood; D002352:Carrier Proteins / Q000097:blood* / Q000302:isolation & purification; D011232:Chemical Precipitation; D003429:Cross Reactions; D004285:Dogs; D005260:Female; D005293:Ferritins / Q000097:blood* / Q000276:immunology / Q000302:isolation & purification; D007070:Immunoglobulin A / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D051381:Rats; D017208:Rats, Wistar
D000936:Antigen-Antibody Complex; D002352:Carrier Proteins; D007070:Immunoglobulin A; D007075:Immunoglobulin M; D005293:Ferritins