Dermatan is a high molecular weight glycosaminoglycan which has been shown to enhance
the inhibition of thrombin by heparin-cofactor II. The aim of this study was to establish
the influence of the molecular size and the role of the carboxyl group on the in vitro
activity of Dermatan Sulfate. Pig skin Dermatan Sulfate was fractionated according
to molecular size by gel-chromatography on Ultrogel Ac 44. Each fraction was characterized
by its sulfur content and by its mean molecular weight measured on a TSK - 4000 column
in reference to standard heparin fractions. Methyl esters of the unfractionated Dermatan
Sulfate with varying degree of esterification, where prepared via activation of the
carboxyl groups with a carbodiimide and reaction with methanol. The results of this
study show that the heparin - cofactor II mediated anti-thrombin activity of Dermatan
Sulfate is increasing with the molecular weight and is abolished by esterification
of the carboxyl groups. Moreover, it can be speculated that each fraction contains
the same amount of high affinity fraction and that, like heparin, the potency of the
high affinity component is increasing with the molecular weight.
