Impaired degradation of chondroitin sulfate in GM2-gangliosidosis.
We have prepared a new radiolabeled substrate, derived from chondroitin 6-sulfate oligosaccharide, for the assaying of chondroitin sulfate degradation by beta-N-acetylgalactosaminidase. Using this substrate, we found a striking deficiency of beta-N-acetylgalactosaminidase activity in the cultured skin fibroblasts of patients with Sandhoff disease and Tay-Sachs disease. DEAE-cellulose chromatography at pH 6.0 revealed that both isoenzymes A and B of beta-N-acetylgalactosaminidases from normal human liver participated in the catabolism of chondroitin 6-sulfate. However, there were major differences in substrate specificity between isoenzyme A and isoenzyme B.
D002478:Cells, Cultured; D002807:Chondroitin / Q000031:analogs & derivatives*; D002809:Chondroitin Sulfates / Q000378:metabolism*; D005347:Fibroblasts / Q000201:enzymology; D006596:Hexosaminidases / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D008099:Liver / Q000201:enzymology; D012497:Sandhoff Disease / Q000201:enzymology*; D012867:Skin / Q000201:enzymology*; D013661:Tay-Sachs Disease / Q000201:enzymology*; D001619:beta-N-Acetylhexosaminidases
D002807:Chondroitin; D002809:Chondroitin Sulfates; D006596:Hexosaminidases; D001619:beta-N-Acetylhexosaminidases