PolyP reduces the mobility of TP proteins in native gels. Two micrograms of protein were incubated with or without 6 µg polyP_>1000and resolved by native PAGE. The gel was stained with Coomassie blue for detection. PolyP binds to and causes a shift in the migration of thrombin (IIa) but does not bind to or affect migration of prothrombin (II). PolyP causes a gel shift in C5b,6, C7, and C8. Results are representative of 4 independent experiments.