Preparation of Polymorphonuclear Leucocyte-Plasma Membranes which Show Fc Receptor Activity

A plasma membrane-rich fraction was prepared from guinea pig peritoneal polymorphonuclear leucocytes (PMNs) by a nitrogen cavitation method. Fc receptor activity was measured in the fraction. The activity showed a Kd of 5×10−7 M IgG and a maximum binding of 33 pmol IgG/mg protein when measured with an immune complex made with bovine serum albumin and rabbit anti-(bovine serum albumin) immunoglobulin G. Properties of the Fc receptor in the plasma membrane fraction were similar to that in intact PMNs. It is proposed that the Fc receptor activity and 5′-nucleotidase activity are markers for plasma membranes of these cells.