Different protein-binding selectivities for N-acyl heparin derivatives having N-phenylacetyl and heterocycle analogs of N-phenylacetyl substituted in place of N-sulfo groups

Replacing N-sulfo groups in heparin with N-arylacyl moieties has been shown to afford charge-reduced heparin derivatives that maintain affinity for select heparin-binding proteins. In this study 50% and 100% N-desulfonated heparins were selectively N-acylated with phenylacetic acid and four phenylacetic acid analogs where the phenyl ring was replaced by a heterocycle. Protein-binding studies reveal that structural differences in the ring systems of the N-acyl groups appended to heparin afford significant affects on affinity and selectivity for different heparin-binding proteins.