Hydration of α-Heparin

Abstract

The sound velocity using sing-around ultrasonic velocimeter and density of aqueous α-heparin solution have been measured at various temperature. The amounts of hydration of α-heparin were calculated from the adiabatic cormpressibility. The values of hydration were 1.04-O.938 (X10-3 m3.kg-1 10-35C) for α-heparin sodium salt and O.647-O.704 (X10-3 m3.kg-1) for α-heparin ion, respectively. These amounts are about twice to five times as large as those of general mono, oligo and polysaceharides. The hydration of α-heparin scarcely depends upon temperature unlike general saccharides. These resultswere explained on the basis of the structure salting-out of the hydroxy and carboxylic groups by the N-sulphate and O-sulphate groups in α-heparin molecule.