The Fc(γ) receptor of rabbit alveolar macrophages was purified by affinity chromatography by using rabbit γ-globulin (Rab(γ)G) coupled to Sepharose. Macrophage preparations were efficiently labeled with 125I by using a modified lactoperoxidase method. After incubation of NP-40 cell lysates with Rab(γ)G-Sepharose, elution at 4°C with 0.5 N acetic acid containing 1% NP-40 and rapid neutralization allowed recovery of active Fc(γ) receptor. Purified Fc(γ) receptor retained its ligand-binding activity, since ~41 to 72% of labeled material specifically rebound to Rab(γ)G-Sepharose. Active receptor also rebound to human IgG- and rat IgG-Sepharose. Active Fc(γ) receptor did not bind to Sepharose coupled to rabbit Fab, rabbit F(ab)'2, or human F(ab)'2 fragments, nor to Sepharose coupled to chicken IgG. analysis of Fc(γ) receptor by SDS-polyacrylamide gels demonstrated a broad peak of radioactivity in the apparent m.w. range of 50,000 to 70,000 in 5.6% acrylamide gels and 35,000 to 55,000 in 9% gels. Labeled receptor with similar structural characteristics and ligand-binding activity was also obtained from highly purified adherent cell populations and from macrophages biosynthetically-labeled with [14C]glucosamine in culture.
|Number of pages||8|
|Journal||Journal of Immunology|
|State||Published - Jan 1 1980|