Characterization of an IgG-Fc Receptor Protein Isolated from Human B-Prolymphocytic and B-Chronic Lymphocytic Leukemia Cells

Abstract

With the exception of antibody-dependent cellular cytotoxicity (18) and immunophagocytosis (11), the biological role of Fc receptors is still largely unclear. Since knowledge of the physicochemical properties of Fc receptors might open up new possibilities for elucidating other biological functions of Fc receptors and the relationship between these receptors and other membrane proteins (6), several attempts have been made to define the physicochemical structure of the Fc receptor molecules. The studies performed so far, however, have not yielded consistent data. In particular, the molecular weight estimated by various authors (3,5,8,16,19,21) varied from 15,000 to 130,000 daltons. These inconsistent estimates of the molecular weight might reflect actual structural heterogeneity of Fc receptors (9) on different types of cells or from different species, or they might be just technical artifacts.