ANALYSIS OF MULTIPLE ANTIGENIC DETERMINANTS OF CLOSTRIDIUM-PERFRINGENS ENTEROTOXIN AS REVEALED BY USE OF DIFFERENT SYNTHETIC PEPTIDES

To identify the antigenic determinants of Clostridium perfringens ente rotoxin (CPE), overlapping peptides corresponding to the entire amino acid sequence of CPE were synthesized and their antigenicity and immun ogenicity were analyzed. Of the 21 synthetic peptides (C-1 to C-21) te sted, peptide C-7 (amino acid residues 91-110) showed the highest reac tivity with rabbit antibodies against CPE. Peptides C-4 (46-65), C-9 ( 121-140), and C-11 (151-170) were reactive with the antibodies, wherea s peptides C-2 (16-35), C-3 (31-50), and C-20 (286-305) were less reac tive. Other peptides were much less reactive. On the other hand, all o f the synthetic peptides reactive with the anti-OPE antibodies were fo und to elicit rabbit antibodies reactive with both their respective an tigens and native CPE molecule. These findings demonstrate that CPE mo lecule contains at least 10 different antigenic determinants which are all immunogenic and supposed to be responsible for functionally and b iologically active sites.