FIG. 4.

Titers of sera from different groups (Gr) of rabbits tested against ETA in ELISA plates coated with 100 ng of ETA per well. Group I rabbits were immunized with peptides 1, 2, 7, and 10 (binding domain); group II rabbits were immunized with peptides 3, 8, and 9 (translocation domain); group IIIa rabbits were immunized with peptides 4, 5, and 6 (enzymatic domain); group IIIb rabbits were immunized with peptide 11 only (enzymatic domain); and group IV rabbits were immunized with native ETA. KLH represents a group of two rabbits immunized with KLH (1 mg per rabbit), the carrier protein used in peptide conjugation. Serum samples from each rabbit were tested in triplicate, and the data are plotted as the mean ± standard error for each group of rabbits.