To study the enzymatic properties of β-galactosidase from the patients with a β-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 β-galactosidase using high performance liquid chromatography (HPLC), optimal reaction conditions were determined for the assay of acid β-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 β-galactosidase and provided an alternative to assays employing radioactive or artificial substrates.
All Science Journal Classification (ASJC) codes
- Clinical Biochemistry
- Biochemistry, medical