Diagnosis of Tay-Sachs disease by estimation of beta-N-acetylhexosaminidase activity using a radiolabeled hyaluronic acid-derived trisaccharide substrate.
We have prepared a new radiolabeled substrate (N-[3H]acetylglucosamine-glucuronic acid-N-[3H]acetylglucosamine), from hyaluronic acid, for an assay of beta-N-acetylhexosaminidase activity. Using this substrate, we found a striking deficiency of beta-N-acetylhexosaminidase activity in cultured skin fibroblasts and in liver homogenates from patients with Tay-Sachs disease. DEAE-cellulose chromatography at pH 6.0 revealed that both isoenzymes A and B of beta-N-acetylhexosaminidase from normal liver participated in the catabolism of hyaluronic acid. There were, however, major differences in substrate specificities between isoenzymes A and B. Our results indicate that this substrate should be useful for enzymatic diagnosis of Tay-Sachs disease.
D002478:Cells, Cultured; D002848:Chromatography, DEAE-Cellulose; D004796:Clinical Enzyme Tests; D005347:Fibroblasts / Q000201:enzymology; D006596:Hexosaminidases / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D008099:Liver / Q000201:enzymology; D013379:Substrate Specificity; D013661:Tay-Sachs Disease / Q000175:diagnosis*; D014312:Trisaccharides / Q000378:metabolism; D001619:beta-N-Acetylhexosaminidases
D007527:Isoenzymes; D014312:Trisaccharides; C041117:N-acetylglucosaminylglucuronic acid-N-acetylglucosamine; D006596:Hexosaminidases; D001619:beta-N-Acetylhexosaminidases