摘要
The serum free medium conditioned by cultured rabbit aortic smooth muscle cells was partially purified using ultrafiltration and heparin affinity chromatography. Incorporation of [￣3H]-thymidine (￣3H-TdR) into cell DNA was used to measure the mitogenic activity of the fractions from chromatography for NIH 3T3 fibroblasts. The molecular weight and the iso-electric point of these fractions were determined by NaDodSO_4-polyacrylamide gel electrophoresis (SDS-PAGE)and iso-electric focusing, respectively. The results showed that the protein eluted in 1.0-1. 6 mol/L NaCl from the heparin-Sepharose was mitogenic for 3T3 cells,and this protein had a molecular weight of 22. 8-26. 7 ku and an iso-electric point of about 4. 6. The fact that the above-mentioned biochemical properties differed from that of PDGF, IGF and FGF suggests that this mitogenic protein may be a separate growth factor.
The serum free medium conditioned by cultured rabbit aortic smooth muscle cells was partially purified using ultrafiltration and heparin affinity chromatography. Incorporation of [￣3H]-thymidine (￣3H-TdR) into cell DNA was used to measure the mitogenic activity of the fractions from chromatography for NIH 3T3 fibroblasts. The molecular weight and the iso-electric point of these fractions were determined by NaDodSO_4-polyacrylamide gel electrophoresis (SDS-PAGE)and iso-electric focusing, respectively. The results showed that the protein eluted in 1.0-1. 6 mol/L NaCl from the heparin-Sepharose was mitogenic for 3T3 cells,and this protein had a molecular weight of 22. 8-26. 7 ku and an iso-electric point of about 4. 6. The fact that the above-mentioned biochemical properties differed from that of PDGF, IGF and FGF suggests that this mitogenic protein may be a separate growth factor.
