A microassay for acid beta-galactosidase activity toward asialofetuin.
To study the enzymatic properties of beta-galactosidase from the patients with a beta-galactosidase deficiency such as GM1 gangliosidosis, determination of enzymatic activity with naturally occurring substrates, asialofetuin in addition to another natural substrate, GM1 ganglioside, is essentially required. With a previously reported, simple and sensitive fluorometric assay for GM1 ganglioside beta-galactosidase using high performance liquid chromatography (HPLC), optimal reaction conditions were determined for the assay of acid beta-galactosidase activity toward asialofetuin in skin fibroblast homogenates. Under these conditions, reduced enzymatic activities could be detected in cultured skin fibroblasts from patients with type 1 and 3 GM1 gangliosidoses and mucopolysaccharidosis IV-B (Morquio B syndrome). This method was applicable to study of the enzymatic properties of the mutant beta-galactosidase and provided an alternative to assays employing radioactive or artificial substrates.
T
T
Mutoh
M
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Naoi
I
I
Sobue
K
K
Kiuchi
T
T
Nagatsu
D001212:Asialoglycoproteins; D002851:Chromatography, High Pressure Liquid; D060748:Fetuins; D005347:Fibroblasts / Q000201:enzymology; D005677:G(M1) Ganglioside; D005696:Galactosidases / Q000378:metabolism*; D005733:Gangliosidoses / Q000201:enzymology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008832:Microchemistry; D012867:Skin / Q000201:enzymology; D013050:Spectrometry, Fluorescence; D000509:alpha-Fetoproteins / Q000378:metabolism*; D001616:beta-Galactosidase / Q000378:metabolism*
D001212:Asialoglycoproteins; D060748:Fetuins; D000509:alpha-Fetoproteins; C017029:asialofetuin; D005677:G(M1) Ganglioside; D005696:Galactosidases; D001616:beta-Galactosidase