Purification and biological properties of a cell growth-stimulating factor from Clostridium perfringens FERM P-14028

The active component that stimulates fibroblast growth was purified from cultured Clostridium perfringens FERM P-14028, and a quantitative assay method for the biological activity was established. The active component was named cell growth-stimulating factor (CGSF), and the molecular weight of this factor was estimated to be 420 kDa on gel permeation chromatography. CGSF(50-100 ng/ml) stimulated the growth rate of BHK-21 (C-13) cells in the logarithmic growth phase, and shortened the doubling time by 16-18%, but had no effect on confluent cells. These actions were indicated only with medium containing fetal bovine serum. These results suggest that CGSF is a novel protein that regulates cell growth via a mechanism of action different from that of other growth factors.