Purification and characterization of Erythroid Differentiation Factor(EDF) isolated from human leukemia cell line THP-1

Abstract

We isolated a protein, from a cell line of human origin, which exhibits extensive differentiation inducing activity toward Friend leukemia cells. The protein, called Erythroid Differentiation Factor(EDF), was found in a 4 day culture of THP-1 cells performed in the presence of 4 β -phorbol 12-myristate 13-acetate(PMA). EDF is a homodimer of a molecular weight of 25,000, with an NH 2-terminal sequence identical to that of the β A-chain of porcine Inhibin. It was suggested that a single protein species is responsible for the activities of both EDF and FRP, a FSH releasing protein isolated from porcine ovarian follicular fluid.