Fig. 2.
Structural basis for a second-generation library. (A) Side view of 3M4E5 Fab in complex with HLA-A*0201/NY-ESO-1157–167, with residues randomized in the second-generation phage display library highlighted as spheres. Colors are as in Fig. 1D. (B–D) Illustrations of 3M4E5 Fab CDR residues that were randomized (red) in the vicinity of the peptide, which displayed nonoptimal contacts with the peptide. Residues making key contacts with the peptide MW side chains and lining the cavity in the CDR loops that interacts with the MW peg are colored in blue. The NYESO-1157–167 peptide is colored cyan, and hydrogen bonds are represented as dashed black lines.