Comparison of equilibrium dissociation constants for the binding of ScFvs to 5-helix determined by ITC and HIV-1 neutralization potency in an Env-pseudotyped neutralization assay.

aITC was carried out at 28°C in 10 mM Tris-HCl, pH 7.6, 150 mM NaCl.bThe neutralization IC50 values for Fab8066, taken from ref. [22], are provided for comparison. The KD for binding to 5-helix, also determined by ITC under the same conditions used for the ScFvs here, is from ref. [35].cSc62 is derived from the parental Fab8062 and has four mutations in the CDR-H2 loop relative to Fab8066/Sc66: I53L, T56F, T57A and N58V.