Fig. 4.

Variation of active single-chain fragment, variable (scFv) concentrations in periplasmic extracts with time at 25°C. (A) ln(% binding rate at time 0) as a function of time. The scFv1F4-WT (diamonds) and mutants R^L24S (circles) and R^L24S/D^L70T (squares) were used at two initial concentrations of 57 and 101, 43 and 95, and 57 and 97 nM, respectively. Mutant D^L70T (triangles) was used at an initial concentration of 30 nM. (B) Histogram representation of the TA₅₀ values calculated for scFv1F4-WT and the three mutants of the H46-H62 pair, in two independent experiments.