Comparison of the amino acid sequences of the variable domains of the heavy chains of mAbs R6H8, OPG2, PAC-1, and LJ-CP3. Multiple-sequence alignment of R6H8, OPG2, PAC-1, and LJ-CP3. The multiple-sequence alignment of individual heavy chains was calculated with the program Clustal Omega⁶⁶ and visualized in Espript.⁶⁷ The highly conserved amino acid residues are presented as white letters on a red background. Amino acid residues that have comparable chemical and physical properties are presented as red letters within blue frames. The RYDG sequence, which begins at amino acid 105 in mAb R6H8, is conserved in all 4 CDR3 sequences.