Fig. 1.

Light chain variable region (VL) amino acid sequences of mutants and surface representations of Fab mutants. (a) VL amino acid sequence of each mutant. L63, L65, L67, L70, and L72 were selected as mutation points. All points were included in framework region 3. The mutants were named R3-mutant, R5-mutant, K5-mutant, D5-mutant, and E5-mutant. (b–f) The electrostatic potentials around the VL binding site of wild type (b), R5-mutant (c), K5-mutant (d), D5-mutant (e), and E5-mutant (f) depicted by using Discovery Studio (ver. 4.5; BIOVIA) with contours drawn at 2 kT per electron at 0.018 mM NaCl (blue for positive and red for negative) by using only full charges. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article)