Figure 5. Comparison of binding affinity of GP_1,2-immunized versus sGP-immunized antisera for sGP and GP_1,2.

(A) Determining apparent K_d value of antibodies from immunized mice for GP_1,2 and sGP. Antiserum from five mice immunized against GP_1,2 and five mice immunized against sGP were individually analyzed by quantitative ELISA using GP_1,2 (blue) or sGP (red) as coating antigen. Scatchard analysis was used to calculate apparent dissociation constants (K_d). (B) Comparison of antibody affinity for GP_1,2 and sGP. Comparison of apparent K_d's of GP_1,2-immunized and sGP-immunized polyclonal antisera for sGP (red) and GP_1,2(blue) was determined by nonlinear regression analysis of Scatchard plots. K_d's for sGP and GP_1,2 were calculated for five individual mice in each group and values for the same animal are connected by a black line.