Characterization of a monoclonal antibody that recognizes an arabinosylated (1-->6)-beta-D-galactan epitope in plant complex carbohydrates.
Monoclonal antibody CCRC-M7 is representative of a group of antibodies with similar binding specificity that were generated using the plant cell-wall pectic polysaccharide, rhamnogalacturonan I, as immunogen. The epitope recognized by CCRC-M7 is present in several plant polysaccharides and membrane glycoproteins. Selective enzymatic or chemical removal of arabinosyl residues from rhamnogalacturonan I reduced, but did not abolish, the ability of CCRC-M7 to bind to the polysaccharide. In contrast, enzymatic removal of both arabinosyl and galactosyl residues from rhamnogalacturonan I completely abolished binding of CCRC-M7 to the resulting polysaccharide. Competitive ELISAs using chemically defined oligosaccharides to compete for the CCRC-M7 binding site showed that oligosaccharides containing (1-->6)-linked beta-D-galactosyl residues were the best competitors among those tested, with the tri-, penta-, and hexa-saccharides being equally effective. The combined results from indirect and competitive ELISAs suggest that the minimal epitope recognized by CCRC-M7 encompasses a (1-->6)-linked beta-galactan containing at least three galactosyl residues with at least one arabinosyl residue attached.
Complex Carbohydrate Research Center, University of Georgia, Athens 30602-4712, USA.
W
W
Steffan
P
P
Kovác
P
P
Albersheim
A G
AG
Darvill
M G
MG
Hahn
D000911:Antibodies, Monoclonal / Q000276:immunology*; D001666:Binding Sites, Antibody; D001667:Binding, Competitive; D002473:Cell Wall / Q000737:chemistry*; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000737:chemistry / Q000276:immunology*; D005685:Galactans / Q000737:chemistry / Q000276:immunology*; D006868:Hydrolysis; D015394:Molecular Structure; D010368:Pectins / Q000737:chemistry / Q000276:immunology*; D010944:Plants / Q000737:chemistry*
D000911:Antibodies, Monoclonal; D000939:Epitopes; D005685:Galactans; C042491:rhamnogalacturonan I; D010368:Pectins; C005653:arabinogalactan