Fig. 6.

PolyP does not interfere with heparin-catalyzed inhibition of thrombin by antithrombin. (A) Residual thrombin activity (A405/min) was measured after incubating 25 nM thrombin with 50 nM antithrombin and 0–1000 U/ml heparin in the absence (○) or presence (●) of 37.5 µM polyP₇₅. The zero point refers to antithrombin inhibition of thrombin without heparin. (B) Residual thrombin activity (A405/min) was measured after incubating 25 nM thrombin with 50 nM antithrombin and 0–375 µM PolyP₇₅ in the absence (○) or presence (●) of 0.01 U/ml heparin. The zero points refer to antithrombin inhibition of thrombin (± heparin) in the absence of polyP₇₅. Data represent mean ± S.D. (n = 3).