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 fr om cultured Clostridium perfringens FERM P-14028, and a quantitative a ssay method for the biological activity was established. The active co mponent was named cell growth-stimulating factor (CGSF), and the molec ular weight of this factor was estimated to be 420 kDa on gel permeati on chromatography. CGSF(50-100 ng/ml) stimulated the growth rate of BH K-21 (C-13) cells in the logarithmic growth phase, and shortened the d oubling time by 16-18%, but had no effect on confluent cells. These ac tions were indicated only with medium containing fetal bovine serum. T hese results suggest that CGSF is a novel protein that regulates cell growth via a mechanism of action different from that of other growth f actors.