Fig. 2. (A) Predicted Lospin reactive center loops (RCL). Lospin RCLs were determined based on the eight-residue pattern (B) that characterizes inhibitory serpins (Hopkins et al., 1993). The residues in the RCL are numbered according to the standard nomenclature (Schechter and Berger, 1967), where residues on the amino-terminal side of the scissile (p1–p1') are not primed and those on the carboxy-terminal side are primed. Assuming that there are 17 residues between the base of RCL hinge and the scissile bond (Hopkins et al., 1993), bold-faced residues are predicted p1 residues with the broken arrow indicating the position of the scissile bond. L1–L17=Lospins 1–17.