heparan sulphate with no affinity for antithrombin iii ( atiii ) was observed to cause acceleration of the factor xa : atiii interaction by 1100-fold ( k2 , 7 x 10 ( 7 ) m-1.min-1 ) and the prothrombinase : atiii interaction by 2900-fold ( k2 , 2.5 x 10 ( 7 ) m-1.min-1 ) .
C0015520
factor xa
C0015518
prothrombinase