BIOSPECIFIC INTERACTIONS OF VITAMIN-K-DEPENDENT FACTORS WITH PHOSPHOLIPID-LIKE POLYSTYRENE DERIVATIVES .2. FACTOR-IX

We previously demonstrated that phosphorylated polystyrene derivatives exhibit phospholipid-like behaviour and therefore are able to interac t with factor II, one of the vitamin K-dependent coagulation factors. Under the same conditions as for factor II, we examined the interactio ns of factor IX with phosphorylated resins of various compositions in phosphate groups: these studies were carried out with or without album in precoating of the polymers and either in the presence or absence of calcium ions. Adsorption experiments show that, in the absence of cal cium ions, only one class of adsorption sites of factor IX can be evid enced with the interactions taking place through the formation of bina ry complexes, whereas in the presence of calcium ions, the affinity of factor IX for phosphorylated resins becomes very high and two types o f adsorption sites have been evidenced with biospecific ternary comple xes being formed. The domains of predominance of these complexes were determined. Moreover, the only functional groups borne by the phosphor ylated polystyrene resins involved in factor IX-polymer interactions a re phosphodiester groups. Comparison between factor II and factor IX a dsorption onto the same polymers leads to the conclusion that the obse rved differences probably reflect the differences in the Gla domains o f the vitamin K-dependent factors. Finally, this study demonstrates th at phosphorylated polystyrene derivatives can be used as stationary ph ases for purification of factor IX by highly specific liquid biochroma tography. (C) 1997 Elsevier Science Limited. All rights reserved.