INTERACTION OF HEPARAN-SULFATE AND ITS FRACTIONS WITH ENDOTHELIAL-CELLS IN CULTURE

In the present work we have investigated the binding capacity, to cell membrane of bovine aortic endothelial cells (BAEC) cultured in vitro, of heparan sulfate (Mr 11.1 kDa) and its four fractions named A (Mr 2 4.5 kDa), B (Mr 10.7 kDad), C (Mr 9.1 kDa) and D (Mr 6.8 kDa). Experim ents were performed in comparison with unfractionated heparin (Mr 12.9 kDa). The binding of the examined compounds was determined by the deg ree of displacement of [H-3]-heparin from the cell membrane. The effic iency of heparan sulfate fractions B, C and D in displacing labelled h eparin was found to decrease in function with the decrease of the mole cular masses of the compounds, [H-3]-heparin could be efficiently disp laced mainly by heparin and fraction A, the fraction which has the hig hest molecular weight and represents only 3.8% of the unfractionated H A 90681. These experimental results may confirm that molecular mass is an important feature for the interaction of glycosaminoglycans with t he specific binding sites on the cell surface.