Glutathione Agarose
-
- Application
- Purification (Purif), Separation (Sep)
- Purpose
- Specific binding and purification of GST-tagged proteins
- Brand
- HighSpec
- Specificity
- Affinity to GST-tagged proteins
- Characteristics
-
- High binding capacity >10 mg/mL.
- Delivered as a 50 % suspension
- Average agarose bead size: 40 μm
- Components
- Affinity Agarose
- Material not included
-
- Lysis Buffer
- Wash Buffer
- Elution Buffer
- Ice bath
- Refrigerated centrifuge for 50 mL tube (min 10,000 x g)
- 50 mL centrifuge tube
- Micropipettor and Micropipetting tips
- Disposable gravity-flow columns with capped bottom outlet, 2 ml
Optional: 15 mL conical propylene tubes pH meter- End-over-end shaker
- UV/VIS Spectrophotometer
- SDS-PAGE buffers, reagents and equipment
Optional: Western Blot reagents and equipment
- Bead Ligand
- Glutathione
- Bead Size
- 40 µm
-
-
- Application Notes
-
For use with: E.coli and eukaryotic cell lysates, cell culture supernatants
Assay Time Procedure: 5-6 h - Comment
-
Sample Volume for an assay: >200 mL E.coli culture volume or corresponding quantity. Protocol can be scaled up easily.
- Protocol
- Purification of GST-tagged protein in batch gravity flow or on FPLC columns
- Reagent Preparation
-
All buffers should be prepared fresh.
- Lysis buffer: Tris-HCl, pH 7.4, 125 mM, NaCl 150 mM, DTT 1 mM, EDTA 1 mM, Lysozyme 1 mg/mL, Triton X-100 1 % (v/v), Protease inhibitor 1x
- Wash buffer: Tris-HCl, pH 7.4, 125 mM, NaCl 150 mM, DTT 1 mM, EDTA 1 mM.
Optional: ATP buffer: Tris HCl, pH 7.4, 50 mM, ATP 2 mM, MgSO4 10 mM - Elution buffer: Tris base, pH 7.4, 125 mM, NaCl 150 mM, Triton X-100 0.1 % (v/v), Reduced glutathione 50 mM, DTT 1 mM
Note: Optimal buffer conditions may vary depending on the protein of interest. Optimal pH can be varied from pH 7.4-8.0. Some proteins may require addition of protease inhibitor cocktail, EDTA, 1-5 mM DTT, 1 % BSA, or detergents such as 0.5-1 % Igepal CA-630 (Nonindet P-40) or 0.5-1 % Tween-20.
- Assay Procedure
-
Protein purification protocol:
- Thaw the E. coli cell pellets corresponding to 200 mL bacterial culture on ice for 15 min. Optional: Freezing the cell pellet at -20 °C for 30 min prior to incubation at room temperature improves lysis by lysozyme.
- Resuspend the cell pellet in 10 mL Lysis Buffer and pour it into a 50 mL conical centrifuge tube. If the solution is very viscous, add 3 units Benzonase® per mL E.coli culture volume to the lysis buffer. Alternatively or additionally, sonicate the lysate to improve cell disruption.
- Incubate on an end-over-end shaker at room temperature for 30 min, or at 4 °C for 1 h, depending on the temperature stability of the protein.
- Centrifuge the lysate at 10.000 x g for 30 min at 2-8 °C and carefully collect the supernatant without touching the pellet. Note: The supernatant contains the cleared lysate fraction. We recommend to take aliquots of all fractions for SDS-PAGE analysis.
- Resuspend the HighSpec Glutathione Agarose by inverting the bottle until the suspension is homogeneous. Transfer 1 mL of the 50 % suspension (corresponding to 500 μL bed volume) into a 15 mL conical centrifuge tube. Allow the resin to settle by gravity and remove the supernatant. Tip: Alternatively, resin equilibration can be performed directly in the disposable gravity flow column.
- Add 5 mL of Wash Buffer and gently resupend the suspension to equilibrate the resin. Allow the resin to settle by gravity and remove the supernatant.
- Add the cleared lysate prepared in step 4 and incubate at 4 °C for 1 h on an end-over-end shaker. Tip: Alternatively, batch binding can be performed directly in a gravity flow column with closed bottom and top outlets.
- Pour the complete suspension into a disposable gravity flow column with a capped bottom outlet.
- Remove the bottom cap of the column and collect the flow-through.
- Wash twice with 2.5 mL each of Wash Buffer.
- Optional: To remove contaminants such as chaperones, perform an additional wash step with ATP buffer.
- Elute the GST-tagged protein by adding 0.5 mL Elution Buffer.
- Repeat step 11 five times, for a total of six elutions. Collect each elution fraction separately. Optional: Incubate the resin for 15 min in Elution Buffer before collecting the eluate to increase protein yields.
- Determine the protein concentration of the elution fractions with Bradford assay, using BSA as protein standard.
- Analyze all fractions by SDS-PAGE. Note: Do not boil membrane proteins. Instead, incubate the sample at 46 °C for 30 min in preparation for SDS-PAGE analysis.
- Optional: Perform Western Blot experiment using GST Antibody.
- Calculation of Results
-
Analyze by SDS-PAGE, Bradford Assay or spectrophotometrically.
- Assay Precision
- 5.5 h
- Restrictions
- For Research Use only
-
- Format
- Liquid
- Storage
- 4 °C
-