| 摘要 |
<p>Factors that act synergistically with tumor necrosis factor (TNF) to induce the expression of tissue factor (thromboplastin or Factor III) in endothelial cells have been isolated. Both protein factors are derived from mouse meth A sarcoma cells. The first is characterized by a molecular weight of 40-50 KDA under non-reducing conditions and 65-75 kDA under reducing conditions and isoelectric points of 6.8 and 7.2. Further characterization includes: loss of activity when treated with protease K, elution from Heparin-Sepharose at 0.5 M NaCl, binding to a reverse phase FPLC-ProRPC column, elution from the reverse phase FPLC-ProRPC column in an ascending methanol gradient at about 50 %, migration as a single band on an SDS-polyacrylamide gel and adsorption to Concanavalin A-Sepharose. The second factor has a molecular weight of 10-30 KDa by gel filtration, loss of activity when treated with trypsin, heat sensitive, elutes from Heparin Ultrogel at 0.5 M NaCl, binds to a Mono Q column and is eluted off in an ascending salt gradient at 0.4 M NaCl.</p> |
