Transforming growth factor betas (TGF Betas) mediate many cell-cell interactions that occur during embryonic development. Three TGF Betas have been identified in mammals. TGF Beta 1, TGF Beta 2, and TGF Beta 3 are each synthesized as precursor proteins that are very similar in that each is cleaved to yield a 113 amino acid polypeptide that remains associated with the latent portion of the molecule.

Expression System

Escherichia coli

Sequence

MALDTNYCFSSTEKNCCVRQLYIDFRKDLGWKWIHEPKGYHANFCLGPCPYIWSLDTQYSKVLALYNQHNPGASAAPCCVPQALEPLPIVYYVGRKPKVEQLSNMIVRSCKCS with polyhistidine tag at the C-terminus.

Species

Human

Tag

polyhistidine tag at the C-terminus

Endotoxin Level

<0.1 EU per 1 μg of the protein by the LAL method.

Activity

Measure by its ability to inhibit the IL-4 dependent proliferation in HT-2 cells.

The ED50 for this effect is <0.1 ng/mL.

The specific activity of recombinant human TGF beat 1 is approximately >5 x 10⁷ IU/mg.

Measure by its ability to induce proliferation in MCF-7 cells.

The ED50 for this effect is <3.2 ng/mL.

Purity

>98% as determined by SDS-PAGE. Ni-NTA chromatography

Formulation

The protein was lyophilized from a solution containing 1X PBS, pH 8.0.

Reconstitution

Unopened ampoules can be stored at -20°C or -80°C.

Need not spin the ampoule. Open the cap carefully, then dissolve the lyophilized protein with sterile water for a 100 μg/mL concentration or acc ording to the product’s Certificate of

Analysis (CoA). (Note: Need not add carrier* to the initial reconstitution solution).

Rinse the inner side of the ampoule gently and stand for at least 20 minutes at room temperature. (Important Note: Do Not Vortex!)

Use the reconstituted solution immediately or store it by distributing it to aliquots and store at -20 °C. (Important Note: Avoid repeated freeze-thaw cycles)

We recommend diluting the solution to working concentration by using buffers or medium containing a carrier*. (Important Note: Do not dilute the working solution with water, which may cause protein degradation.)

*Carriers: 0.1% BSA or 5% HSA or 10% FBS.