Inducibility of protein-reactive antibodies by peptide immunization: comparison of three epitope peptides of hen egg-white lysozyme.
Three epitope peptides of hen egg-white lysozyme (HEL) were tested for ability to induce antibodies reactive with native HEL. Each peptide was coupled to bovine gamma-globulin (B gamma G) and 4 rabbits were immunized with each peptide-B gamma G conjugate in complete Freund's adjuvant. The mean association constants (K0s) of HEL-reactive antibodies (HEL-R-Abs) from each immunizing group to [3H]acetyl HEL or to [3H]acetyl-peptide were measured in solution by a double antibody method. Only peptide loop I.II (sequences 57-107 containing Cys64-Cys80 and Cys76-Cys94) induced high-affinity antibodies to HEL (K0 = 2.5 x 10(6)-2.3 x 10(7) M-1) among the three epitope peptides tested. The association constants of antipeptide loop I.II to [3H]acetyl peptide loop I.II were always one to two orders of magnitude higher than those to HEL. In addition, 50 to 80% of the anti-peptide loop I.II antibodies were reactive with native HEL. The specificity of anti-peptide loop I.II was directed to a conformational feature of the peptide rather than to native HEL and reactivity of the antibody to HEL was interpreted as a kind of cross-reaction. The HEL-R-Abs from anti-Ploop I.II antisera also manifested neutralizing activities against the enzymic activity of HEL when Micrococcus luteus was used as the substrate.
Seki
J
J
Department of Immunochemistry, Osaka University.
Wang
X
X
Ota
A
A
Suzuki
Y
Y
Sakato
N
N
Fujio
H
H
D000818:Animals; D000906:Antibodies / Q000032:analysis* / Q000276:immunology; D004527:Egg Proteins / Q000276:immunology*; D000939:Epitopes / Q000276:immunology*; D007114:Immunization; D009113:Muramidase / Q000276:immunology*; D010455:Peptides / Q000276:immunology; D011817:Rabbits; D014316:Tritium
D000906:Antibodies; D004527:Egg Proteins; D000939:Epitopes; D010455:Peptides; D014316:Tritium; D009113:Muramidase