(A) Alignment of Fsn0503 variable domains and designed Fsn0503h human variable domains. Amino acid residues mutated from the murine sequence are highlighted. CDRs are boxed. (B) 4-20% SDS gel analysis showed the highly purified cathepsin S antibodies: Lane 1 -- Fsn0503h; Lane 2 -- Fsn0503; Lane 3 - Human isotype antibody control; Lane 4 -- SeeBlue plus marker. (C) Compeptitive immunoreactivity profile: Fsn0503h & Fsn0503 was allowed to compete with a biotin-labeled Fsn0503 (120 nM) for binding to recombinant Fsn0503 mature antigen (40 nM). (D) Pharmacokinetic analysis of Fsn0503h in rats. Following a single i.v. administration of Fsn0503h using a bi-exponential model (linear scale), it showed that the initial half-life value of Fsn0503h was 14.8 hours with a terminal half-life of 274 hours (approximately 11.4 days).