Evidence for two different active sites on human beta-hexosaminidase A. Interaction of GM2 activator protein with beta-hexosaminidase A.
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چکیده
منابع مشابه
In Cellulo Examination of a Beta-Alpha Hybrid Construct of Beta-Hexosaminidase A Subunits, Reported to Interact with the GM2 Activator Protein and Hydrolyze GM2 Ganglioside
The hydrolysis in lysosomes of GM2 ganglioside to GM3 ganglioside requires the correct synthesis, intracellular assembly and transport of three separate gene products; i.e., the alpha and beta subunits of heterodimeric beta-hexosaminidase A, E.C. # 3.2.1.52 (encoded by the HEXA and HEXB genes, respectively), and the GM2-activator protein (GM2AP, encoded by the GM2A gene). Mutations in any one o...
متن کاملCombined replacement effects of human modified β-hexosaminidase B and GM2 activator protein on GM2 gangliosidoses fibroblasts
GM2 gangliosidoses are autosomal recessive lysosomal storage diseases (LSDs) caused by mutations in the HEXA, HEXB and GM2A genes, which encode the human lysosomal β-hexosaminidase (Hex) α- and β-subunits, and GM2 activator protein (GM2A), respectively. These diseases are associated with excessive accumulation of GM2 ganglioside (GM2) in the brains of patients with neurological symptoms. Here w...
متن کاملHydrolysis of Tay-Sachs ganglioside by beta-hexosaminidase A of human liver and urine.
A crude /I-hexosaminidase fraction prepared by (NH,),SO( fractionation of human liver extract or urine was found to convert Tay-Sachs ganglioside, GalNAcPl -+ 4(NANcrZ -+ 3)Gal/31 --f 4Glc + ceramide (G& into NAN& + 3Galfil -+ 4 Glc + ceramide (GMM3). After separation of hexosaminidase A and B by DEAE-cellulose chromatography, only freshly prepared fi-hexosaminidase A hydrolyzed GM2 although bo...
متن کاملLysosomes and human liver disease: a biochemical and immunohistochemical study of beta-hexosaminidase.
Liver biopsies from 88 patients with different liver diseases were studied for beta-hexosaminidase activity. Liver specimens with normal light microscopical morphology showed no immunohistochemical reactivity for beta-hexosaminidase. Increased reactions were noted, mainly in hepatocytes, in biopsies from the patients with different liver diseases. A very large interindividual variation of bioch...
متن کاملLow levels of beta hexosaminidase A in healthy individuals with apparent deficiency of this enzyme.
Appreciable beta hexosaminidase A (hex A) activity has been detected in cultured skin fibroblasts and melanoma tissue from healthy individuals previously reported as having deficiency of hex A activity indistinguishable from that of patients with Tay-Sachs disease (TSD). Identification and quantitation of hex A, amounting to 3.5%-6.9% of total beta hexosaminidase activity, has been obtained by ...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1985
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(17)39645-x