A monoclonal antibody to feruloylated-(1→4)-β- d -galactan

We report the isolation and characterization of a monoclonal antibody, designated LM9, against feruloylated-(1→4)-β- d -galactan. This epitope is a structural feature of cell wall pectic polysaccharides of plants belonging to the family Amaranthaceae (including the Chenopodiaceae). Immuno-assays and immunofluorescence microscopy indicated that LM9 binding is specific to samples and cell walls obtained from species belonging to this family. In a series of competitive-inhibition enzyme-linked immunosorbent assays with potential oligosaccharide haptens, the most effective inhibitor was O -[6- O -( trans -feruloyl)-β- d -galactopyranosyl]-(1→4)- d -galactopyranose (Gal 2 F). LM9 is therefore a useful antibody probe for the analysis of phenolic substitution of cell wall pectic polymers and of cell wall structure in the Amaranthaceae including sugar beet ( Beta vulgaris L.) and spinach ( Spinacia oleracea L.).