Human platelet factor 4: Purification and characterization by affinity chromatography. Purification of human platelet factor 4.
Platelet factor 4 is a low molecular weight protein contained in the storage granules of platelets and released during aggregation with a variety of aggregating agents. In vitro, it is a potent antiheparin. This property has been used for a rapid, simple purification procedure using affinity chromatography on heparin epsilon-aminocaproic aced Sepharose. Supernatants collected from outdated platelet concentrates, or platelet extracts prepared from washed, outdate platlets themselves, are first precipitated with 50% ammonium sulfate. The supernatant is dialyzed and applied to the affinity column. Contaminating proteins are washed from the column with 0.5 M NaCl in 0.005 M sodium barbital buffer, pH 7.4 and the column is then eluted with a gradient of 0.5 to 3.0 M NaCl in 0.005 M sodium barbital buffer, pH 7.4. When prepared from platelet extracts, a single protein peak with high platelet factor 4 activity is eluted at 0.9 to 1.0 M NaCl. The peak fractions demonstrate a single band on Na dodecyl-SO4-polyacrylamide gel electrophoresis. The molecular weight as determined by Na dodecyl-SO4 gel electrophoresis was 11,600 +/- 330, and was 40,000 by gel filtration.
D000596:Amino Acids / Q000032:analysis; D001779:Blood Coagulation Factors / Q000032:analysis*; D002846:Chromatography, Affinity; D004355:Drug Stability; D006358:Hot Temperature; D006801:Humans; D005779:Immunodiffusion; D008055:Lipids / Q000032:analysis; D008970:Molecular Weight; D010978:Platelet Factor 4 / Q000032:analysis* / Q000302:isolation & purification
D000596:Amino Acids; D001779:Blood Coagulation Factors; D008055:Lipids; D010978:Platelet Factor 4