Table 5

Summary of BIAcore analysis mutants of RFB4-PE38

Binding kinetics were analyzed on a BIAcore 2000 Biosensor (BIAcore). On and off rates were measured by injecting immunotoxins at a concentration of 380 nm over a CM5 sensor chip (BIAcore) containing immobilized CD22. Bound material was allowed to dissociate for 5 min or more.
ImmunotoxinKon (M−1S−1)Koff (S−1)Kda (nm)
GSSY (WT)2.08 × 1041.77 × 10−385
GTHW3.27 × 1042.07 × 10−46
GYNW1.84 × 1041.91 × 10−410
GTTW2.62 × 1046.5 × 10−424
GSTY3.15 × 1041.55 × 10−349
  • a Kd was calculated by dividing Koff by Kon.