FIG. 8.
Effect of molecular weight of type III capsule upon lectin site inhibition. The extent to which increasing concentrations of type III oligosaccharides with an average Mr of 5,900 (open bars), an Mr of 22,500 (stippled bars), or native (intact) type III GBS CPS (closed bars) inhibited PMN-mediated opsonophagocytosis of type III GBS by nonimmune serum is shown. At 500 μg/ml, native type III GBS CPS effected significantly greater mean (± SEM) inhibition of the lectin site (100%) than did the smaller (30% ± 10% inhibition [P = 0.002]) or larger (46% ± 12% inhibition [P = 0.02]) type III GBS oligosaccharides.