Liposome immune lysis assay (LILA) for gelonin

• Published in: Journal of immunological methods Vol. 148; no. 1-2; p. 151
• Main Authors: Paul, A, Madan, S, Vasandani, V M, Ghosh, P C, Bachhawat, B K
• Format: Journal Article
• Language: English
• Published: Netherlands 1992
• Subjects: Binding, Competitive; Blotting, Western; Cross Reactions; Cytotoxicity Tests, Immunologic - methods; Fluoresceins; Immunodiffusion; Indicators and Reagents; Liposomes; Plant Proteins - analysis; Plant Proteins - immunology; Protein Synthesis Inhibitors - analysis; Ribosome Inactivating Proteins, Type 1; Ricin - immunology; Sensitivity and Specificity
• ISSN: 0022-1759
• DOI: 10.1016/0022-1759(92)90168-S

A complement-mediated liposome immune lysis assay using entrapped calcein was developed for a plant toxin gelonin. Gelonin was covalently coupled to DPPE, and then adsorbed on to the surface of liposomes. Such antigen-bearing liposomes when incubated with anti-gelonin antibody in the presence of guinea pig complement undergo lysis. The detection range is from 3 ng to 60 ng. The method was used to monitor isolation of gelonin by affinity chromatography. It was observed that a minor peak in addition to the major one comes with gelonin, shared common epitopes/epitope with gelonin in immunological reaction. This was further confirmed by SDS-gel electrophoresis indicating the former being an isoform of gelonin. A comparative study of the immunocross-reactivity of ricin and ricin A chain with anti-gelonin antibody was carried out. It was found that while ricin A chain cross-reacted extensively with gelonin antibody and intact ricin elicited little or no cross-reactivity. It is suggested that the present LILA may be employed for the detection and quantitation of ricin A chain by this LILA method.