Photo-conjugation of Z domain probes to mouse IgG1.

(A): Analysis by SDS-PAGE of the mouse IgG1 mAb photocoupling efficiency of nine different ZWT- or ZF5I-based probes, differing in the position of the maleimide benzophenone (MBP) group. As indicated, variants containing the MBP group at positions 2, 3, 4, 9, 11, 15, 24 or 32 were investigated. (B): Analysis by SDS-PAGE of the photocoupling efficiency of the ZWT-Q32C-MBP and ZF5I-Q32C-MBP probes, both containing the MBP group at position 32, to 19 different mouse IgG1 mAbs (see Material and Methods for a list). The designations HC+P, HC, LC and P, refer to heavy chain+probe, heavy chain, light chain and probe, respectively. The M lanes refer to marker protein with molecular weights in kDa as indicated.