Pulse-chase experiments had shown that @-hexosaminidase was synthesized in cultured human fibroblasts in precursor form and that during maturation of the enzyme the a-chains were converted from Mr = 67,000 to 54,000 and the /&chains from M, = 63,000 to 29,000 plus smaller fragments, probably through an intermediate form of M, = 52,000 (Hasilik, A., and Neufeld, E. F. (1980) J. Biol. Chem. 255,4...

beta-Hexosaminidase B purified from human fibroblast secretions was used as a ligand to study phosphomannosyl-enzyme receptors in membranes from rat tissues. Enzyme binding to rat liver membranes was saturable, competitively inhibited by mannose 6-phosphate, not dependent on calcium, and destroyed by prior treatment of the hexosaminidase with either alkaline phosphatase or endoglycosidase H. Mo...

Tay–Sachs disease is a severe lysosomal storage disorder caused by mutations in the HEXA gene coding for α subunit of lysosomal β-Hexosaminidase A enzyme, which converts GM2 to GM3 ganglioside. HexA−/− mice, depleted of the β-Hexosaminidase A iso-enzyme, remain asymptomatic up to 1 year of age because of a metabolic bypass by neuraminidase(s). These enzymes remove a sialic acid residue converti...

Hexosaminidase C was separated from human brain supernatant by immunoadsorption of the A and B forms on to a column of immobilized antibody followed by preparative starch-block electrophoresis. There were some differences in the properties of hexosaminidase C preparations after each of these stages, shown by comparison of their heat-inactivation characteristics and filtration through Bio-Gel P-...

We have generated mouse models of human Tay-Sachs and Sandhoff diseases by targeted disruption of the Hexa (alpha subunit) or Hexb (beta subunit) genes, respectively, encoding lysosomal beta-hexosaminidase A (structure, alpha) and B (structure, beta beta). Both mutant mice accumulate GM2 ganglioside in brain, much more so in Hexb -/- mice, and the latter also accumulate glycolipid GA2. Hexa -/-...

Tay-Sachs disease is a severe lysosomal disorder caused by mutations in the HexA gene coding for the α-subunit of lysosomal β-hexosaminidase A, which converts G(M2) to G(M3) ganglioside. Hexa(-/-) mice, depleted of β-hexosaminidase A, remain asymptomatic to 1 year of age, because they catabolise G(M2) ganglioside via a lysosomal sialidase into glycolipid G(A2), which is further processed by β-h...

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...

the mucopolysaccharidoses are a clinically and genetically heterogenous group of lysosomal storage diseases caused by defects in different enzymes for mucopolysaccharid degradation (glycosaminoglycans). except for mucopolysaccharide storage disease type ii (hunter disease), all are transmitted through an autosomal recessive mode of inheritanceinheritance. clinical feature of these metabolic dis...

rendered background IgE levels only. In accordance, sera of OVA mice which permitted mast cell degranulation upon OVA trigger in a specific b-hexosaminidase release assay, whereas sera of OVA-AAVLP mice did not contain anaphylactogenic antibodies. In an in vivo anaphylaxis experiment, upon intravenous OVA challenge OVA-immunized mice presented significant drop of body temperature, whereas AAVLP...