when blood plasma containing the nh2-terminal 12-residue peptide ( n-peptide ) of alpha 2-plasmin inhibitor ( alpha 2pi ; alpha 2-antiplasmin ) was clotted in the presence of calcium ions , the n-peptide and alpha 2pi were cross-linked to fibrin by activated coagulation factor xiii .
C0032105
blood plasma
C0015982
fibrin