Effects of PK on thrombin generation in plasma. (A) Thrombin generation in PK-deficient plasma induced to clot with PTT-A reagent. Reactions were run in the absence of PK (vehicle; solid gray line) or in the presence of 600 nM plasma PK (pPK; heavy solid line), PK-WT (dashed line), PK-R371A (dotted line), or PK-S559A (dash-dotted line). (B) Same as panel A, but no PTT-A reagent was added. (C) Thrombin-generation parameters derived from the curves in panel A. Each curve represents means for reactions run in triplicate.