Alignment of serpin C termini. C termini of serpins present in the hemostatic system and (*) identical, (:) conserved, or (.) semiconserved substitutions are shown. The C terminus of α2AP extends approximately 55 amino acids beyond the C termini of the other hemostatic serpins. The 6 lysine residues (K) in the α2AP C terminus are shown in bold, and the RGD sequence is underlined. The alignment was made with ClustalW2.⁶⁷  (●) Sulfated tyrosine residue (Y). α1AT, α-1-antitrypsin; ATIII, antithrombin III; HCII, heparin cofactor II; PCI, protein C inhibitor; PZRPI, protein Z–related protease inhibitor.