• Purity

  >90%, by SDS-PAGE under reducing conditions and visualized by Colloidal Coomassie® Blue stain at 5 μg per lane

• Endotoxin Level

  <1.0 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its ability to hydrolyze the substrate 4-Nitrocatechol Sulfate (PNCS). The specific activity is >0.3 pmol/min/μg, as measured under the described conditions. See Activity Assay Protocol on .

• Source

  Spodoptera frugiperda,     Sf 21 (baculovirus)-derived Arg23-Leu502 with a C-terminal 6-His tag

• Accession #

• N-terminal Sequence    
  Analysis

  Arg23

• Predicted Molecular Mass

  55 kDa

• SDS-PAGE

  55-63 kDa, reducing conditions

Assay Procedure

Materials

• Assay Buffer: 50 mM MES, pH 5.5

• Recombinant Human Sulfamidase/SGSH (rhSGSH) (Catalog # 8380-SU)

• Substrate: 4-Nitrocatechol Sulfate (PNCS) (Sigma, Catalog # N7251), 100 mM stock in deionized water

• Sodium Hydroxide (NaOH) (Sigma, Catalog # 221465), 2 M stock in deionized water

• 96-well Clear Plate (Catalog # )

• Plate Reader (Model: SpectraMax Plus by Molecular Devices) or equivalent

1. Dilute rhSGSH to 40 µg/mL in Assay Buffer.

2. Dilute PNCS to 20 mM in Assay Buffer.

3. Combine 150 µL of 40 µg/mL of rhSGSH and 150 µL of 20 mM of PNCS in microtubes. Include a Substrate Blank with 150 µL of Assay Buffer and 150 µL of 20 mM of PNCS.

4. Incubate at 37 °C for 72 hours.

5. Stop reactions and Substrate Blank by adding 300 µL of 0.2 M NaOH to each tube.

6. Load 200µL from each stopped reaction and Substrate Blank vial into a plate.

7. Read plate at 510 nm (absorbance) in endpoint mode.

8. Calculate specific activity:

   *Adjusted for Substrate Blank
   **Derived using calibration standard 4-Nitrocatechol (PNC) (Sigma, Catalog # N15553).

Per Well:

• rhSGSH: 2 µg

• Substrate: 5 mM
  

Background: Sulfamidase/SGSH

Also known as N-sulfoglucosamine sulfohydrolase and heparan N-sulfatase, Sulfamidase/SGSH is an important member of the sulfatase family involved in the degradation of heparan sulfate (HS) (1). Different from the HS specific endosulfatases that remove sulfate from internal GlcNAc residues (2), SGSH removes sulfate group from the non-reducing end glucosamine residues on HS. The SGSH deficiency results in mucopolysaccharidosis type IIIA (MPS IIIA, Sanfilippo A syndrome), an autosomal recessive lysosomal storage disease characterized by neurological dysfunction but relatively mild somatic manifestations (3). Human SGSH shows 88.6% sequence identity with that of mouse sequence.

• References:

1. DiezRoux, G. and Ballabio, A. et al. (2005) Annu. Rev. Genomics Hum. Genet. 6:355.

2. Morimoto-Tomita, M. et al. (2002) J. Biol. Chem. 277:49175.

3. Blanch, L. et al. (1997) Hum. Mol. Genet. 6:787.

• Entrez Gene IDs:

  6448 (Human); 27029 (Mouse)

• Alternate Names:

  heparan sulfate sulfatase; HSS; HSSN-sulphoglucosamine sulphohydrolase; MPS3A; MPS3Asulphamidase; N-sulfoglucosamine sulfohydrolase; SFMD; SFMDEC 3.10.1.1; SGSH; Sulfamidase; Sulfoglucosamine sulfamidase; Sulphamidase