ISSN:
1432-0533
Keywords:
GM2 Gangliosidosis
;
Juvenile Type
;
Biochemistry
;
Hexosaminidase A
;
Altered Substrate Specifity
;
Galactosaminidase
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The N-acetyl-β-d-hexosaminidases A and B were extracted from the liver tissue of a patient who died from juvenile GM2-gangliosidosis at the age of $$14{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}$$ years. The enzymes were separated from each other and studied in comparison to enzyme preparations from normal tissue. The kinetic parameters studied (pH profiles, Michaelis constants, heat lability) and the substrate specificity of the B-enzyme appeared normal. The activity of the A-enzyme against two artificial substrates was lowered in the pathological tissue to 53% and 41% of the control and to 27% of the control against the storage compound trihexosylceramide (ceramide-glucose-galactose-N-acetylgalactosamine). Furthermore, using the main storage compound ganglioside GM2 (ceramide-glucose-galactose-[N-acetylneuraminic acid]-N-acetylgalactosamine) as substrate, no N-acetyl-β-d-galactosaminidase activity was found in the extracts from pathological liver tissue.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00687632
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