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  • G7673 - α-Galactosidase I, Alkaline from Cucumis melo

G7673 Sigma-Aldrich

α-Galactosidase I, Alkaline from Cucumis melo

Synonym: α-D-Galactoside Galactohydrolase, Melibiase



Related Categories 3.2.x.x Glycosidases, 3.x.x.x Hydrolases, Application Index, Biochemicals and Reagents, Carbohydrate Hydrolysis,
Quality Level   200
recombinant   expressed in E. coli
assay   ≥85% (SDS-PAGE)
activity   ≥20 units/mg protein
mol wt   apparent mol wt ~84 kDa by SDS-PAGE
shipped in   wet ice
storage temp.   −20°C


General description

Alkaline α-Galactosidase I is a glycoside hydrolase, separated from the extracts of melon fruits. The activity of this enzyme is found to increase during the early stages of ovary development and fruit set.


Alkaline α-Galactosidase I was used to assay enzyme activity with 2 mmp-nitrophenyl-α-d-galactoside as substrate at pH 6.5 to compare with the enzyme activity of α-Gal A isolated and purified from Sf-9 insect cells infected with a recombinant baculovirus encoding normal α-Gal A gene.

Biochem/physiol Actions

α-Galactosidase form I from melon may play a significant role in photoassimilate partitioning in sink tissue. The form I enzyme has a preferred activity with raffinose and significant activity with stachyose. A unique feature of this enzyme is that it exhibits weak product inhibition by galactose.

This enzyme shows a preference for raffinose and also activity with stachyose. Unlike other a-Galctosidases, this enyzme also shows weak inhibition by galactose.

Physical properties

This enzyme exhibits maximal activity between 30-37°C. Activity declines above 40°C.

Unit Definition

One unit will hydrolyze 1.0 μmole of p-nitrophenyl α-D-galactoside to p-nitrophenol and D-galactose per minute at pH 7.8 at 30 °C.

Physical form

The product is supplied as a lyophilized powder containing Tris-HCl buffer salts, DTT, EDTA, and NaCl.

Safety & Documentation

Safety Information

GHS07  GHS07
Signal word 
Hazard statements 
Precautionary statements 
NONH for all modes of transport
WGK Germany 
Protocols & Articles

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