Binding of hD1D2 mutants to collagenlike peptides in a plate assay. (A) Binding of the 4 human-to-murine D1D2 mutants to CRP (▴) or GPP10 (▵), compared with the binding of wild-type hD1D2 to CRP (▪) or to GPP10 (□), and of wild-type mD1D2 to CRP (•) or to GPP10 (○). (B) Binding of hD1D2 (wild type, ▪) and the 6 hD1D2 “alanine” mutants (▴) to CRP or to GPP10 (□ and ▵ for wild type and mutants, respectively) at a range of concentrations of hD1D2. Mean ± SD for 3 separate experiments.