Comparison of physical and immunological properties of plasma membranes of two mouse leukemia cell lines, P388 and L1210.

A method for the isolation of the plasma membranes of the mouse leukemic cell P388 is described. The method includes surface labeling of the cell membrane with 125I. The 125I specific activity of the plasma membrane preparation is 10- to 13-fold higher than that of the cell homogenate; enzyme assays and electron microscopy further corroborate the purity of the P388 plasma membrane preparation. The predominant iodinated membrane proteins have molecular weights of 85,000, 66,000, and 13,000 daltons. Antibodies prepared against P388 and L1210 plasma membranes inhibit the growth of the corresponding cells in the absence of complement. They show cross-reactivity to each other but do not affect the growth of HeLa cells.