Wu V Y, Walz D A, McCoy L E
Prep Biochem. 1977;7(6):479-93. doi: 10.1080/00327487708065515.
Platelet antiheparin, platelet factor 4, was isolated from freeze-thaw lysates of fresh bovine and outdated human platelet concentrates by a single step affinity chromatographic procedure.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.
血小板抗肝素，即血小板第4因子（PF4），通过一步亲和层析法从新鲜牛血小板浓缩物和过期人血小板浓缩物的冻融裂解物中分离得到。人源和牛源血小板的PF4产量分别为93微克/毫升和142微克/毫升。牛源分离物的产物抗肝素活性为558单位/毫克，人源物质的为489单位/毫克。牛源产物是一种单链多肽，表观分子量为12300。氨基酸组成表明其有107 - 109个残基，相比之下，较小的人源产物是一种70个残基的多肽，表观分子量为8000。完整的多肽对酶解具有抗性，而还原烷基化衍生物在有肝素和无肝素存在的情况下均易被水解。
