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 of 125I-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 pM 125I-D-factor. M1 cells showed a high affinity for 125I-D-factor (dissociation constant, 1.0 × 10-10 M) and expressed a small number of binding sites (170 per cell). Specific binding of 125I-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.
Yamamoto-Yamaguchi, Y., Tomida, M., & Hozumi, M. (1986). Specific binding of a factor inducing differentiation to mouse myeloid leukemic M1 cells. Experimental Cell Research, 164(1), 97–102. https://doi.org/10.1016/0014-4827(86)90457-X