from the kinetics of prothrombinase activity , an interaction between factor xa and both factor v and factor va was observed , with apparent 1:1 stoichiometries and dissociation constants of 7.3 x 10 ( -10 ) m for factor va and 2.7 x 10 ( -9 ) m for factor v .
C0015498
factor v
C0015501
factor va