1,721,188 research outputs found
Identification of beta-N-acetylhexosaminidase A in mouse tissue with the fluorigenic substrate 4-methylumbelliferyl-beta-N-acetylglucosamine 6-sulphate.
No full textbeta-N-Acetylhexosaminidase from mouse tissue was separated into its constituent isoenzymes on DEAE-cellulose and its activity was monitored with 4-methylumbelliferyl-beta-N-acetylglucosamine and 4-methylumbelliferyl-beta-N-acetylglucosamine 6-sulphate. Forms corresponding to the human isoenzymes A (acidic), B (basic) and an 'intermediate' form were present in mouse liver and spleen, whereas in kidney the B and 'intermediate' forms predominated, with A present only as a minor component. In brain the 'intermediate', A and C activities were detected. Testis had predominantly A activity, whereas epididymis, the tissue with the highest specific activity of beta-N-acetylhexosaminidase, had an abundance of the 'intermediate' form, but was almost entirely lacking in the A form
Lysosomal alpha-D-mannosidase
No full textalpha-mannosidosis in the human is an autosomal recessive lysosomal storage disease caused by a deficiency of lysosomal alpha-D-mannosidasea actvity. Lysosomal alpha-D-mannosidase is involved in the catabolism of N linked glycoproteins through the sequential degradation of high-mannose, hybrid and complex oligosaccharides. This review is focused on human, mouse, bovine and feline genes coding for lysosomal alpha-D-mannosidase, In particular the exon-intron structure of the genes, their promoters, and the identification of mutations causing the disease have been examined. The construction, by homologous recombination, of a mouse model of alpha-mannosidosis is reported
Elevated beta-N-acetylhexosaminidase activity in focal dystonia fibroblasts
No full textSpecific activities of beta-D-hexosaminidase, alpha-D-mannosidase, beta-D-galactosidase and beta-D-glucuronidase were determined in fibroblasts of patients with writer's cramp and torticollis. These diseases show degenerative neurological disorders similar to those observed in lysosomal diseases. Hexosaminidase specific activities, determined using 4-methylumbelliferyl-beta-N-acetylglucopyranoside and 4-methylumbelliferyl-beta-N-acetylglucopyranoside-6-sulphate as substrates, were significantly higher in the fibroblasts of patients than in controls. No significant differences were observed in the specific activities of the other lysosomal enzymes. The increased hexosaminidase specific activities in torticollis and writer's cramp may be additional markers for these diseases
Modulation of β-N-acethyl-D-glucosaminidase activity by a lectin (Concanavalin A) in cultured fibroblasts.
No full textIsolation of beta-hexosaminidase isoenzymes from annelidis by phenyl boronate agarose chromatography.
No full textElevated beta-N-acetylhexosaminidase activity in focal dystonia fibroblasts
No full textSpecific activities of beta-D-hexosaminidase, alpha-D-mannosidase, beta-D-galactosidase and beta-D-glucuronidase were determined in fibroblasts of patients with writer's cramp and torticollis. These diseases show degenerative neurological disorders similar to those observed in lysosomal diseases. Hexosaminidase specific activities, determined using 4-methylumbelliferyl-beta-N-acetylglucopyranoside and 4-methylumbelliferyl-beta-N-acetylglucopyranoside-6-sulphate as substrates, were significantly higher in the fibroblasts of patients than in controls. No significant differences were observed in the specific activities of the other lysosomal enzymes. The increased hexosaminidase specific activities in torticollis and writer's cramp may be additional markers for these diseases
Calcium ionophore A-23187 inhibits the secretion of β-hexosaminidase from the GG2EE mouse macrophage cell line
No full textSecretion of the lysosomal enzyme β-N-acetylhexosaminidase is inhibited by calcium ionophore A-23187 in the GG2EE macrophage cell line. Such inhibition is time and dose dependent. Calcium ionophore A-23187 treatment causes a change in the pattern of hexosaminidase isoenzymes detectable in the cell extract, as assessed by DEAE-cellulose chromatography. In particular, control cells show two hexosaminidase isoenzymes corresponding to hexosaminidase A and B, whereas cells treated with calcium ionophore A-23187 express a third isoenzyme form with properties similar to hexosaminidase S
Immobilized henylboronic acid chromatography for the isolation of an atypical beta-hexosaminidase form in human-leukemic lymphocytes.
No full textCloning and sequence analysis of cDNA encoding the alpha-sub-unit of mouse beta-N-acetylhexosaminidase and comparison with the human enzyme
No full textcDNAs encoding the mouse beta-N-acetylhexosaminidase alpha-subunit were isolated from a mouse testis library. The longest of these (1.7 kb) was sequenced and showed 83% similarity with the human alpha-subunit cDNA sequence. The 5' end of the coding sequence was obtained from a genomic DNA clone. Alignment of the human and mouse sequences showed that all three putative N-glycosylation sites are conserved, but that the mouse alpha-subunit has an additional site towards the C-terminus. All eight cysteines in the human sequence are conserved in the mouse. There are an additional two cysteines in the mouse alpha-subunit signal peptide. All amino acids affected in Tay-Sachs-disease mutations are conserved in the mouse
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