Production and Characterization of Monoclonal Antibodies against Wheat Flour Diacylgalactosylglycerols

Abstract

Seven immunoglobulin M (IgM)-type monoclonal antibodies were developed against wheat diacylgalactosylglycerols (MGDG). That with the highest titer, MG405, was characterized in detail using a solid phase enzyme-linked immunosorbent assay (ELISA). Inhibition experiments with galactose, glycerol, galactosylglycerol, and lipid standards containing fatty acids typical of those in MGDG indicated that MG405 was directed against the whole MGDG molecule rather than parts of its structure. Six other monoclonal antibodies, also IgM type, had similar specificities. Antibody binding was reduced by 30% when fetal bovine serum, used as antibody diluent and blocking agent, was replaced with gelatin in an ELISA carried out with purified MG405. The plasma cofactor β2-glycoprotein I (β2GPI) increased binding only slightly, suggesting that some other plasma cofactor may potentiate antibody binding to MGDG. MG405 also appeared not to be an intrinsically low-affinity antibody to β2GPI. Availability of antibodies such as MG405 could provide a valuable means of investigating polar lipid functionality in foods. Keywords: Anti-glycolipid antibody; monoclonal antibody; diacylgalactosylglycerols; MGDG; wheat; bread dough gas retention.