Inhibitory effect of SS-CS/DS oligosaccharides and fraction M on the binding of PTN to immobilized SS-CS/DS. A fixed concentration of HGF (50 ng) was mixed with each size-defined SS-CS/DS oligosaccharide fraction produced by CSase AC-I, the isolated hexasaccharide ΔA-iB-iB, or the parental SS-CS/DS polysaccharide fraction, and incubated for 15 min. Interactions of the HGF in each sample with immobilized E-CS/DS were analyzed using a BIAcore system as described under “Experimental Procedures.” A, the inhibitory activity of a series of SS-CS/DS oligosaccharide fractions (di-, tetra-, hexa-, octa-, deca-, and >decasaccharide (larger than deca-)) and native SS-CS/DS (10 μg/ml each) was compared. B, the inhibitory activity of fraction M (10 pmol) was compared with that of the parental SS-CS/DS hexasaccharide mixture (500 pmol) obtained in Fig. 3.