Fig. 2.

Identification of LY3300054 epitope residues in human PD-L1. Panel a: CLUSTALW multiple sequence alignment of domain 1 of human (hu-PD-L1), canine (ca-PD-L1), and murine (mu-PD-L1) PD-L1 and human PD-L2 (huPD-L2) to identify LY3300054 a subset of the specificity anchors on hu-PD-L1. Underlined is the human PD-1 6Ǻ binding site on hu-PD-L1 (according to PDB: 4ZQK (26602187)). An alignment position is marked with (*) if both mu-PD-L1 and ca-PD-L1 substitutions differ from the hu-PD-L1 sequence. An alignment position is marked with (:) if either the mu-PD-L1 or ca-PD-L1 substitution differs from the hu-PD-L1 sequence. Panel b: Position N63 on human PD-L1 is a specificity anchor for LY3300054. Canine-to-human mutation K63 N (▲)Wild type ca-PD-L1-Fc (ty, human-to-canine mutant N69H (△). ELISA was repeated twice with three technical replicates for each concentration