Purification and characterization of human and bovine platelet factor 4.
Platelet antiheparin, platelet factor 4, was isolated from freeze-thaw lysates of fresh bovine and outdated human platelet concentrates by a single step affinity chromatographic procedure. The yields of PF4 were 93 microgram and 142 microgram/ml of human and bovine platelets respectively. Antiheparin activity of the products were 558 units/mg for the bovine isolate and 489 units/mg for the human material. The bovine product is a single chain polypeptide with an apparent molecular weight of 12,300. Amino acid composition indicates 107-109 residues compared to the smaller human product which has an apparent molecular weight of 8,000 for a 70 residue polypeptide. The intact polypeptide was resistant to enzymatic hydrolysis as opposed to the reduced-alkylated derivative which was susceptible to hydrolysis in the presence and absence of heparin.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001779:Blood Coagulation Factors / Q000302:isolation & purification; D002417:Cattle; D002918:Chymotrypsin; D006801:Humans; D008970:Molecular Weight; D010434:Pepsin A; D010446:Peptide Fragments / Q000032:analysis; D010978:Platelet Factor 4 / Q000302:isolation & purification; D013045:Species Specificity; D014357:Trypsin
D000596:Amino Acids; D001779:Blood Coagulation Factors; D010446:Peptide Fragments; D010978:Platelet Factor 4; D002918:Chymotrypsin; D014357:Trypsin; D010434:Pepsin A