ppack dihydrochloride is the dihydrochloride form of its active component ppack (d-phenylalanyl-l-prolyl-l-arginine chloromethyl ketone), a potent, selective and irreversible inhibitor of thrombin that inhibits human α-thrombin with inhibition constant kivalue of 0.24 nm. ppack covalently binds to the specific active-site ser of thrombin and cross links with his57 at the binding site forming a tetrahedral ppack-thrombin complex. the complex further binds to and saturates the high-affinity functional thrombin receptors eventually leading to the inhibition of thrombin activation. ppack is currently being investigated as an anti-coagulant to prevent blood coagulation. study results show that ppack is able to dose-dependently inhibit thrombin-induced platelet accumulation.jun t. liu, william paul, michael emerson, carla cicala and clive p. page. thrombin inhibitors and anti-coagulants on thrombin-induced embolization in rabbit cranial vasculature. european journal of pharmacology 264 (1994) 183-190ildiko m. kovach, paul kelley, carol eddy, frank jordan and ahmet baykal. proton bridging in the interactions of thrombin with small inhibitors. biochemistry. 2009; 48(30): 7296-7304martha e. lyon, james s. fine, paul j. henderson and andrew w. lyon. d-phenylalanyl-l-prolyl-l-arginine chloromethyl ketone (ppack): alternative anticoagulant to heparin salts for blood gas and electrolyte specimens. clin. chem. 41/7, 1038-1041 (1995)
