BIOSPECIFIC INTERACTIONS OF VITAMIN-K-DEPENDENT FACTORS WITH PHOSPHOLIPID-LIKE POLYSTYRENE DERIVATIVES .1. FACTOR-II

Phosphorylated polystyrene derivatives with different compositions in phosphate groups were shown to be either recognized as phospholipidic or as DNA-like surfaces by antibodies from Systemic Lupus Erythematosu s patients. In order to check whether these polymers were able to inte ract with Vitamin K-dependent coagulation factors, phosphorylated resi ns of various compositions in phosphate groups were assessed with rega rd to their interactions with Factor II, one of the Vitamin K-dependen t factors. These studies were performed either in the presence or the absence of calcium ions, and with or without albumin precoating of the polymers. The results show that the affinity of the protein for the p olymer is increased in the presence of calcium ions and depends on the composition of the polymer. The protein-polymer interactions involve the formation of binary or ternary complexes and the domains of predom inance of these complexes were determined as a function of the calcium ion concentration in the assay. This allowed us to propose optimal co nditions for Factor II purification by highly specific liquid chromato graphy using phosphorylated polystyrene resins of given compositions a s stationary phases.