Interaction of heparin with annexin V

Abstract

The energetics and kinetics of the interaction of heparin with the Ca+2 and phospholipid binding protein annexin V, was examined and the minimum oligosaccharide sequence within heparin that binds annexin V was identified. Affinity chromatography studies confirmed the Ca+2 dependence of this binding interaction. Analysis of the data obtained from surface plasmon resonance afforded a K(d) of ~21 nM for the interaction of annexin V with end-chain immobilized heparin and a K(d) of ~49 nM for the interaction with end-chain immobilized heparan sulfate. Isothermal titration calorimetry showed the minimum annexin V binding oligosaccharide sequence within heparin corresponds to an octasaccharide sequence. The K(d) of a heparin octasaccharide binding to annexin V was ~1 μM with a binding stoichiometry of 1:1. Copyright (C) 1999 Federation of European Biochemical Societies.