FIGURE 5.

IC₅₀ values for the binding of HS antibodies to immobilized HS in the presence of heparin oligosaccharides of various length and full-length heparin. PMHS was biotinylated and immobilized on streptavidin-coated microtiter plates. Equilibrium binding of HS antibodies in the presence of heparin oligosaccharides, dp2–dp12 and full-length heparin (FL) was quantified at A₄₉₀ using a VSV-G tag antibody (P5D4) followed by HRP-conjugated anti-mouse antibody and o-phenylenediamine substrate. The range of heparin oligosaccharides was extended to dp12–dp20 for HS3B7V. The IC₅₀ values were calculated as the concentrations of competitor saccharide required for 50% inhibition of antibody binding to immobilized HS. The values are the means of triplicate samples, the error bars represent the S.E., and the data are representative of two separate experiments. * denotes oligosaccharides unable to compete sufficiently to calculate an IC₅₀.