Purification and properties of bacterially synthesized human granulocyte-macrophage colony stimulating factor

Abstract

Human granulocyte-macrophage colony stimulating factor (GM-CSF) has been synthesized in high yield using a temperature inducible plasmid in Escherichia coli. The human GM-CSF is readily isolated from the bacterial proteins because of its differential solubility and chromatographic properties. The bacterially synthesized form of the human GM-CSF contains an extra methionine residue at position 1, but otherwise it is identical to the polypeptide predicted from the cDNA sequence. The specific activity of 2.9 x 107 units/mg of protein for purified bacterially synthesized human GM-CSF indicates that despite the lack of glycosylation, the molecule is substantially in its native conformation. This ..