Microanalysis and characterization of acidic glycosaminoglycans in human tissues

Abstract

The acid glycosaminoglycans (AG) were isolated from small quantities of human tissue (1.0 gm wet weight or less) and were separated, identified, and measured by zone electrophoresis on cellulose acetate. The major AG components in human skin, sclera, and cornea were identified and measured. The amount of Alcian Blue (dye used to stain the AG) bound to each AG polymer on the cellulose acetate strip was dependent on the number of moles of disaccharide repeating units (DRU) times the number of dissociated carboxylic and sulfate groups per DRU. The degree of dissociation of these groups depended on their corresponding p K's and the pH of the Alcian Blue solution. The glucosamine/galactosamine fraction agreed closely with the hyaluronic acid/sulfated AG (dermatan sulfate + chondroitin 4 6 - sulfate ) fraction obtained by electrophoresis. The mobility of each AG polymer was affected more by the number of negative charges per DRU than by the molecular weight. The identity and number of charged groups per DRU could be deduced from the electrophoretic mobilities and the dye binding data. The combined use of chemical analyses and zone electrophoresis permitted the major AG polymers to be identified and measured in tissues without the use of ion-exchange columns.