Steffan W, Kovác P, Albersheim P, Darvill A G, Hahn M G
Complex Carbohydrate Research Center, University of Georgia, Athens 30602-4712, USA.
Carbohydr Res. 1995 Oct 2;275(2):295-307. doi: 10.1016/0008-6215(95)00174-r.
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.
单克隆抗体CCRC - M7是一组具有相似结合特异性的抗体的代表，这些抗体是用植物细胞壁果胶多糖鼠李半乳糖醛酸聚糖I作为免疫原产生的。CCRC - M7识别的表位存在于几种植物多糖和膜糖蛋白中。从鼠李半乳糖醛酸聚糖I中选择性地酶促或化学去除阿拉伯糖基残基会降低但不会消除CCRC - M7与该多糖结合的能力。相反，从鼠李半乳糖醛酸聚糖I中酶促去除阿拉伯糖基和半乳糖基残基会完全消除CCRC - M7与所得多糖的结合。使用化学定义的寡糖竞争CCRC - M7结合位点的竞争性酶联免疫吸附测定表明，含有（1→6）连接的β - D - 半乳糖基残基的寡糖是所测试的寡糖中最佳的竞争者，三糖、五糖和六糖同样有效。间接和竞争性酶联免疫吸附测定的综合结果表明，CCRC - M7识别的最小表位包括一个（1→6）连接的β - 半乳聚糖，其含有至少三个半乳糖基残基且连接有至少一个阿拉伯糖基残基。
