Molecular properties of a granulocyte/macrophage colony-stimulating factor obtained from the serum-free culture of Yoshida sarcoma cell Line YSSF-212T.

A granulocyte/macrophage colony-stimulating factor (Peak-1 CSF) was partially purified from the medium of a serum-free culture of Yoshida sarcoma cells (Line YSSF-212T). Its elution position in gel-filtration chromatography corresponded to a molecular weight of about 22,000. The factor had an isoelectric point at pH 4.5 and a sedimentation coefficient of 2.3 S. The major part of its activity was not bound by Concanavalin A-Sepharose. Although CSF activity behaved as a single component in the gel-filtration and isoelectrofocussing procedures, subsequently it was resolved into two species by preparative discontinuous polyacrylamide gel-electrophoresis. This resolution indicates microheterogeneity of the CSF molecule. Oxidation with periodate readily inactivated L . P3-cell CSF, but the YSSF-cell CSF was fairly resistant. Moreover, titration with anti-L cell CSF serum showed a definite difference between L . P3-cell CSF and YSSF-cell CSF.