Fig. 2.

(A) Sites of mutation in αCD3 Fab for the single and double conjugates. Each mutant conjugate results in a distinct orientation for PSMA binding relative to CD3 binding. The double-αCD3 conjugate (HC-K138/LC-S202) increases avidity to homodimeric PSMA. (B) FACS of the P-αCD3 (100 nM) conjugates on Jurkat (CD3⁺) and C4-2 (PSMA⁺) cell lines. P-Phthal is conjugated to different positions of the αCD3 Fab. (C) FACS analysis of the binding of different mono- and bivalent P-αCD3 conjugates to C4-2 cells at various concentrations.