Description:

1. Sequencing-grade Sialidase A (N-acetylneuraminate glycohydrolase, EC3.2.1.18) cleaves all non-reducing terminal sialic acid residues from complex carbohydrates and glycoproteins (Figure 1). The relative cleavage rates for different linkages are: "(2-6) > "(2-3) > "(2-8),"(2-9). In addition, Sialidase A will cleave branched sialic acids (linked to an internal residue). This property makes it unique among sialidases. High concentrations of enzymes and prolonged incubation times may be required for cleaving branched residues.


2. Sialidase A, because of its purity and broad linkage specificity, has been extensively used in the analysis of both glycoproteins and glycolipids (Uchida et al., 1977; Parekh et al., 1985).

Sialidase A is useful for:

1. Structural analysis of oligosaccharides.
2. Determining sialic acid linkage (in conjunction with other sialidases having different specificities, such as Sialidase C and Sialidase S; Glycoprotein deglycosylation.
3. Removing heterogeneity from Glycoproteins

Source:

1. E. coli

Specific Activity:

1. >40 Units/mg.

Storage/Handling:

1. Store at 4°C. DO NOT FREEZE Shipped on ice pack for next day delivery.

Formulation:

1. A sterile-filtered solution in 20 mM Tris-HCl, 25 mM NaCl (pH 7.5)

Stability:

1. Stable at least 12 months when stored properly. Several days exposure to ambient temperatures will not reduce activity.


2. Molecular Weight: ~88 kD

pH Range:

1. Optimum: pH 6.0
2. Range: pH 4.5 - 8

Source:

1. E. coli

Suggested: Procedure for De-sialylation

1. 1. Add up to 100 μg of glycoprotein or 1 nmole of oligosaccharide to a tube.
Note: To cleave more than one nmole of substrate, increase reaction volume and enzyme proportionally.
2. 2. Add de-ionized water to a total of 14 :l.
3. 3. Add 4 :l 5x Reaction Buffer.μ
4. 4. Add 2 :l Sialidase A.
5. 5. Incubate at 37EC for 1 hour.
Note: longer incubation times are necessary if branched sialic acids are present.

De-sialylation may be monitored by SDS-PAGE if the size differential between native and de-sialylated protein is sufficient for detection.