Effect of in-vitro addition of sulfated xylans, glucosans or chondroitins on the prothrombin time of human plasma and on the enhancement of activation of glutamic plasminogen by tissue plasminogen activator

Abstract

Three each of sulfated xylans, glucosans or chondroitins were investigated. A comparison of the infrared analysis of the native and sulfated amylopectin showed the presence of peaks corresponding to 800/cm for S-O and 1200-1300/cm for S=O only in the sulfated amylopectin and earlier results using C NMR showed sulfation of hyroxymethyl groups (C-6) of amylopectin. Based upon % sulfate the three classes of compounds following sulfation contained more than one sulfate group per sugar unit. All of them exhibited significant in-vitro anticoagulant property by inhibiting thrombin generation at very low concentrations. In general sulfated xylans or glucosans were better anticoagulants than the chondroitins. The results of in-vitro studies of the activation of glutamic plasminogen (Glu-Plg) by tissue plasminogen activator (t-PA) using 0.05 mol/l Tris buffer (pH 7.35) containing physiological concentration of NaCl (0.9%), showed that oat spelts xylan sulfate and amylopectin sulfate gave a 20-fold enhancement of the activation in a synergistic manner when used in combination with 32.4 mmol/l of lysine. The mechanism of enhancement was investigated by dilution studies. Sulfated amylopectin interacted with Glu-Plg but not with t-PA and lysine which interacted with both Glu-Plg and t-PA enhanced the activation in a synergistic manner using low concentrations of t-PA.