Abstract
Heparin was immobilized onto BrCN-activated Sepharose gel us ing α,ω-diaminopoly(ethylene oxide) (diamino PEO) with various chain lengths as a spacer. The heparin activity was measured on the basis of prolongation of activated partial thromboplastin time (APTT). The activity of immobilized heparin was observed after the amino groups at the terminal end of the spacer molecule, not used for immobilization of heparin, were blocked with formalde hyde. The flexible PEO spacer appeared to relieve the steric hindrance by the carrier to the formation of a heparin complex with cofactor AT III. The activity of immobilized heparin increased with elongation of the spacer chain and the highest activity was obtained when the chain length of the spacer was between 10 to 20. Longer spacer groups decreased the activity because the high mobil ity of the hydrated PEO chain hindered AT III access to the immobilized heparin.
Get full access to this article
View all access options for this article.