β-Galactosidase

β-Galactosidase, EIA grade, is a lyophilizate from E. coli overproducer, consisting of enzyme protein, phosphate buffer, and sucrose. Substances which could interfere with the derivatization of NH₂ or SH groups (e.g., 2-mercaptoethanol, ammonium salts, primary amines etc.) have been removed.

The GLB1 (β-Galactosidase) gene is mapped to human chromosome 3p22.3. The encoded protein belongs to glycosyl hydrolase 35 family and is localized to lysosomes.

β-Galactosidase has been used as a standard to determine the absolute quantitation of LacZ protein.

β-Galactosidase is used for labeling enzyme immunoassay techniques. β-Galactosidase can be coupled to other proteins via its SH-groups. The reconstituted solution can be used directly for conjugation without prior dialysis or gel permeation chromatography.

β-Galactosidase catalyzes the hydrolysis of terminal β-galactose residue of ganglioside substrates, such as glycoproteins, sphingolipids, and keratan sulfate and other glycoconjugates. This enzyme is associated with the mechanism of cell senescence and carcinogenesis. Mutations in the gene result in gangliosidosis, an autosomal recessive disorder, characterized with defective lysosomal storage due to accumulation of substrates. β-Galactosidase deficiency also causes Morquio B syndrome indicating skeletal abnormalities, short stature and increased excretion of keratan sulfate in urine.

Lyophilizate, stabilized with phosphate buffer and sucrose. Note: Contains at least 12 free SH-groups/enzyme molecule; 5 mg approximately 20 mg lyophilizate; 25 mg approximately 100 mg lyophilizate.

Store at -15–-25 °C. (sealed under nitrogen)

Purity: single peak (HPLC)

Specific activity: approximately 750 - 950 U/mg enzyme protein ≅ approximately 150 - 250 U/mg lyophilizate (+37°C, 2-nitrophenyl-β-D-galactoside); approximately 250-400 U/mg enzyme protein ≅ approximately 60-100 U/mg lyophilizate (+37°C, 4-nitrophenyl-β-D-galactoside).

仅用于生命科学研究。不可用于诊断。

Free Thiol Groups
The non-denatured, enzymatically-active preparation contains > 12 SH groups per molecule which are not involved in disulfide bridges and are freely accessible to coupling reagents in aqueous media (as assayed with Ellman′s reagent at +37 °C, acc. to Habeeb, 1972).

Absence of Enzyme Aggregates
The preparation contains < 3% dimers (HPLC, area %) and essentially no higher oligomers.