Isolation of a high molecular mass granulocyte colony-stimulating factor from bovine lung conditioned medium

A high molecular mass type of granulocyte colony-stimulating factor (CSF-F) from bovine lung tissue produced by fibroblasts was isolated and partially purified by a four-step procedure. Following ammonium sulfate fractionation, hydrophobic interaction, ion-exchange and affinity chromatography, CSF-F was more than 200-fold enriched. CSF-F was found to be a glycoprotein of approximately 68 kDa with an isoelectric point of 4.0-5.2. It did not lose its biological activity after neuraminidase treatment. Gel-filtration behavior of desialo-CSF-F was not changed.