A001 Affinity of low molecular weight fucoidan for P-selectin triggers its binding to activated human platelets

Results The fucoidan prevented P-selectin binding to Sialyl Lewis X with an IC50 of 20 nM as compared to 400 nM for heparin and >25000 nM for dextran sulfate. It exhibited the highest affinity for immobilized Pselectin with a KD of 1.2 nM, two orders of magnitude greater than the KD of the other polysaccharides. Mass spectrometry evidenced the formation of a complex between P-selectin and fucoidan. The intensity of the fucoidan binding to platelets was dependent on the level of platelet activation. Competition between fucoidan and an anti P-selectin antibody demonstrated the specificity of the interaction. General significance Low molecular weight fucoidan is a promising therapeutic agent of natural origin for biomedical applications. Affinity of low molecular weight fucoidan for P-selectin triggers its binding to activated human platelets. Bachelet L, Bertholon I, Lavigne D, Vassy R, Jandrot-Perrus M, Chaubet F, Letourneur D. Biochim Biophys Acta. 2008 Nov 5.