A simple method for increasing hapten immunogenicity by a specific structural modification of the carrier

A simple procedure to bind haptens, drugs or Peptides selectively through their amino or carboxylic group to a spacer arm modified non-immunogenic polypeptide is described. Gelatin, a well known non-immunogenic carrier, was modified by blocking its amino groups. Spacer arms with primary amino groups such as beta-alanine or ethylenediamine were conjugated to this protein by carbodiimide resulting in spacer modified gelatin. These modified polypeptides were tested for their ability to selectively bind haptens through their amino or carboxylic groups. Three probes were used and the results obtained confirm the hypothesis. Three conjugates obtained were further used to induce an immune response in mice. Enhancement of the immunogenicity of these spacer-arm supported haptens was observed. Overall, this study provides a rational approach to the production of well defined antigens using a simple conjugation technique.