MBP Nanoselector Agarose

Description: 

MBP Nanoselector Agarose have been specifically designed to bind MBP-fusion proteins. MBP Nanoselector Agarose is based on small high-affinity recombinant alpaca antibody fragments covalently coupled to the surface of Agarose. MBP Nanoselector Agarose is an ideal tool to isolate or purify MBP-fusion proteins fast and efficiently.

Ligand: Anti-MBP single domain antibody fragment (VHH, Nanobody)
Bead size: ~ 40µm
Reactivity: Recognizes MBP or MBP fusion protein.
Binding capacity: High binding capacity, 10 µL slurry bind about 20 µg of recombinant MBP.
Storage: Shipped at ambient temperature. Upon receipt store at 4°C. Stable for 1 year. Do not freeze.
Storage Buffer: 50 % slurry in PBS containing 20 % Ethanol

Background: 

MBP is used to increase the solubility of recombinant proteins expressed in E. coli. In these systems, the protein of interest is often expressed as a MBP-fusion protein, preventing aggregation of the protein of interest. The mechanism by which MBP increases solubility is not well understood. In addition, MBP can itself be used as an affinity tag for purification of recombinant proteins. The fusion protein binds to amylose columns while all other proteins flow through.MBP Nanoselector Agarose is an affinity resin for immunoprecipitation of MBP fusion proteins. The MBP Nanoselector consists of an MBP Nanobody/ VHH coupled to agarose beads.

Immunoprecipitation (IP)/Co-IP
Mass spectrometry (MS)
Enzyme activity measurements

Immunoprecipitation protocol

Mammalian cell lysis

Note: Harvesting of cells and cell lysis should be performed with ice-cold buffers. We strongly recommend to add protease inhibitors to the Lysis buffer to prevent degradation of your target protein and its binding partners.

For one immunoprecipitation reaction, we recommend using ~10⁶- 10⁷ cells.

1. Choice of lysis buffer:

* For cytoplasmic proteins, resuspend the cell pellet in 200 µL ice-cold Lysis buffer by pipetting up and down. Supplement Lysis buffer with protease inhibitor cocktail and 1 mM PMSF (not included).

* For nuclear/chromatin proteins, resuspend cell pellet in 200 µL ice-cold RIPA buffer supplemented with DNaseI (f.c. 75-150 Kunitz U/mL), MgCl2 (f.c. 2.5 mM), protease inhibitor cocktail and PMSF(f.c. 1 mM)(not included)

2. Place the tube on ice for 30 min and extensively pipette the suspension every 10 min.

3. Centrifuge cell lysate at 17,000x g for 10 min at +4°C. Transfer cleared lysate (supernatant) to a pre cooled tube and add 300 µL Dilution buffer supplemented with 1 mM PMSF and protease inhibitor cocktail (not included). If required, save 50 µL of diluted lysate for further analysis (input fraction).

Bead equilibration

1. Resuspend the beads by gently pipetting up and down or by inverting the tube. Do not vortex the beads!

2. Transfer 25 µL of bead slurry into a 1.5 mL reaction tube.

3. Add 500 µL ice-cold Dilution buffer.

4. Sediment the beads by centrifugation at 2,500x g for 5 min at +4°C.

5. Discard the supernatant.

Protein binding

1. Add diluted lysate to the equilibrated beads.

2. Rotate end-over-end for 1 hour at +4°C.

Washing

1. Sediment the beads by centrifugation at 2,500x g for 5 min at +4°C.

2. If required, save 50 µL of supernatant for further analysis(flow-through/non-bound fraction).

3. Discard remaining supernatant.

4. Resuspend beads in 500 µL Wash buffer.

5. Sediment the beads by centrifugation at 2,500x g for 5 min at +4°C. Discard the remaining supernatant.

6. Repeat this step at least twice.

7. During the last washing step, transfer the beads to a new tube.

Optional: To increase stringency of the Wash buffer, test various salt concentrations e.g. 150 mM - 500 mM,and/or add a non-ionic detergent e.g. Triton™ X-100.

Elution with 2x SDS-sample buffer

1. Remove the remaining supernatant.

2. Resuspend beads in 80 µL 2x SDS-sample buffer.

3. Boil beads for 5 min at +95°C to dissociate immunocomplexes from beads.

4. Sediment the beads by centrifugation at 2,500x g for 2 min at +4°C.

5. Analyze the supernatant in SDS-PAGE.

Elution with Glycine-elution buffer

1. Remove the remaining supernatant.

2. Add 50–100 µL Glycine-elution buffer and constantly pipette up and down for 30 - 60 sec at +4°C.

3. Sediment the beads by centrifugation at 2,500x g for 5 min at +4°C.

4. Transfer the supernatant to a new tube.

5. Immediately neutralize the eluate fraction with Neutralization buffer.

6. Repeat this step at least once to increase elution efficiency .