Interaction of fibrinogen with dextran sulfate.

Interactions of fibrinogen with dextran sulfate, dextran, and carboxymethyl cellulose were investigated by turbidity measurement, chemical analysis, and electrophoresis. Dextran sulfate and fibrinogen combined even in the physiological pH region where both of them have negative net charges, and formed a precipitate and soluble complex. Since no complex formation was observed in the case of dextran, it seems that the electrostatic force plays a part in complex formation. However, sodium carboxymethyl cellulose which carries -COO(-) groups did not combine with fibrinogen. Therefore, it is considered that there is a specificity for the interaction among ionized groups. Further, temperature and molecular size of dextran sulfate influenced the interaction to a large extent. It is concluded from these facts that other intermolecular binding forces should be taken into consideration in addition to the electrostatic force.