A factor inducing differentiation of mouse myeloid leukemic M1 cells into macrophages (differentiation-inducing factor, D-factor), which was purified to homogeneity from conditioned medium of mouse Ehrlich ascites tumor cells, could be iodinated without detectable loss of biological activity. The binding of125I-D-factor to M1 cells was specific; the binding was inhibited competitively by D-factor derived from Ehrlich cells and mouse fibroblast L929 cells, but not by other growth factors or D-factor derived from differentiated M1 cells. The latter differs from D-factor of Ehrlich cells and L929 cells in antigenicity and molecular weight. At 21 °C, the binding was saturated at 370 pM125I-D-factor. M1 cells showed a high affinity for125I-D-factor (dissociation constant, 1.0 × 10-10M) and expressed a small number of binding sites (170 per cell). Specific binding of125I-D-factor was observed only to several clones derived from Ml cells, including those sensitive and resistant to induction of differentiation by D-factor. © 1986.
Mendeley saves you time finding and organizing research
Choose a citation style from the tabs below