Characterization of Monoclonal Antibodies and Corresponding Epitopes of Vibrio vulnificus

Abstract

Monoclonal antibody (Mab) P3C3 raised against V. vulnificus reacted with nine of thirteen V. vulnificus strains. In comparison, Mab P3F10 reacted with only three V. vulnificus strains. No cross-reactions were observed among fourteen non-V. vulnificus strains. P3C3 and P3F10 isotypes were characterized as IgG1k. When examined via an indirect fluorescent antibody procedure, epitopes that were recognized by the P3C3 and P3F10 Mabs were found to be on the cell surface. Results of an additivity test suggest that these two epitopes are at different positions on the cell surface. The number of P3F10 epitopes on the TG617 strain was larger than the number of P3C3 epitopes. In addition, the former. was probably physically more accessible than the latter. The resultant additive index suggested that the binding of Mab P3F10 to its corresponding epitopes interferes in three dimensions with the binding of Mab P3C3 to its epitopes; however, the reverse is not true. Epitope P3C3 was shown to be a protein with a molecular weight of 40 kDa, but epitope P3F10 was shown to be a glycopeptide with a molecular weight ranging from 10 to 21 kDa.