Fig. 2

Identifying the carbohydrate moiety (ies) and defining the conformational epitope. JM1-24-3 interacts with the glycosylated MUC18 protein expressed on the cell surface of melanoma cells Treatment of WM266-4 cells with tunicamycin significantly reduced JM1-24-3 binding with MUC18 as shown by FACS (p < 0.01) a and showed reduced forms of MUC18 (110 and 90 kDa) by WB b. FLISA competition assay with WM266-4 cell membrane fraction showed that JM1-24-3 binding to MUC18 glycoprotein is significantly competed by lectin SNL c. JM1-24-3 binds to the epitopes of MUC18 on melanoma cell surface JM1-24-3 binding with WM266-4 is competitively reduced by MUC18 binding peptides, P1-BSA, P2-BSA and P3-BSA individually as shown by serial dilutions of Ab d or in combination e as shown by serial dilutions of peptides by FACS. The competitive interference achieved with combination of three peptides was greater than that achieved with the individual peptides