- Other Names
- Inhibin BA (INHBA), Inhibin B-1, Follicule stimulating hormone-releasing protein (FRP), FSH releasing protein, FSH releasing factor, Erythroid differentiation factor (EDF)
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- Product Citations
Activin A was initially identified in ovarian fluid as a stimulator of FSH secretion from anterior pituitary cells. Activin A is a member of the TGFb1 family which includes TGFs, activins, Nodal, growth and differentiation factors (GDF), and bone morphogenetic proteins (BMPs). Activin A is a dimer of the beta A subunits of human inhibin; the beta A subunit binds the beta B subunit of inhibin to form Activin AB. The beta B subunit also exists as a heterodimer to form Activin B. Activin A binds two type I and two type II serine/threonine kinase receptors at the same time. The type II receptor kinase is constitutively active and phosphorylates the type I receptor after the formation of the ligand-receptor complex. Five type II receptors have been identified: ActRIIA, ActRIIB, BMPRII, TGFβRII, and MISRII. ActRIIB binds to Activin A, BMP-2, BMP-7, GDF-8, and GDF-11. The type I receptors are named activin receptor-like kinases 1 to 7 (ALK1~7), and Activins bind to ALK4 and ALK7. Follistatin (FS) is a natural Activin A antagonist; FS neutralizes its biologic activities by preventing Activin A interaction with its receptors. Activin A has pleiotropic functions. It is a morphogen during embryonal development, regulating chondrogenic and osteogenic differentiation of mesenchymal progenitor cells (MPC). Activin A has been associated with neuroprotection, apoptosis, and fibrosis. Also, high levels of Activin A have been found in synovial fluid from patients with rheumatoid arthritis, inflammatory bowel disease, and gout. In addition, it has been speculated that Activin A, in collaboration with TGFb1 and IL-25, promotes TH9 generation and the development of allergic pathology.Product Details
- Human Activin A, amino acids (Gly311-Ser426) (Accession# M13436) was expressed in CHO cells.
- Molecular Mass
- The 116 amino acid recombinant protein has a predicted molecular mass of approximately 12.9 kD. The DTT-reduced and non-reduced glycosylated protein migrate at approximately 14 kD and 26 kD respectively by SDS-PAGE. The N-terminal amino acid is Gly.
- >95%, as determined by Coomassie stained SDS-PAGE.
- 0.22 µm filtered protein solution is in 0.1% TFA, <30% ACN.
- Endotoxin Level
- Less than 0.01 ng per µg cytokine as determined by the LAL method.
- 10 and 25 µg sizes are bottled at 200 µg/mL. 100 µg size and larger sizes are lot-specific and bottled at the concentration indicated on the vial (please contact technical support for concentration, or use our Lookup tool if you have a lot number.) Please note, new lots of the 100 µg size will be lot-specific and may differ from previous lots that had a fixed concentration.
- Storage & Handling
- Unopened vial can be stored between 2°C and 8°C for three months, at -20°C for six months, or at -70°C for one year. For maximum results, quick spin vial prior to opening. Stock solutions should be prepared at no less than 10 µg/mL in sterile buffer (PBS, HPBS, DPBS, and EBSS) containing carrier protein such as 1% BSA or HSA. After dilution, the cytokine can be stored between 2°C and 8°C for one month or from -20°C to -70°C for up to 3 months. Avoid repeated freeze/thaw cycles.
- ED50 = 1 - 5 ng/ml, corresponding to a specific activity of 0.2 - 1.0 x 106 units/mg, as determined by cytotoxic effect on MPC-11 mouse plasmacytoma cells.
- Application Notes
BioLegend carrier-free recombinant proteins provided in liquid format are shipped on blue-ice. Our comparison testing data indicates that when handled and stored as recommended, the liquid format has equal or better stability and shelf-life compared to commercially available lyophilized proteins after reconstitution. Our liquid proteins are validated in-house to maintain activity after shipping on blue ice and are backed by our 100% satisfaction guarantee. If you have any concerns, contact us at firstname.lastname@example.org.
- Activin A is expressed by a wide range of cells such as BM-derived stromal fibroblasts, aortic smooth muscle cells, pulmonary epithelium, CD4 T cells.
- Activin A plays a key role in embryogenesis, neointimal formation after arterial injury, early stages of chondrogenesis, osteogenesis, and hemopoiesis. Activin A drives TH9 differentiation in vitro. It is induced by Angiotensin II and alpha Thrombin and regulated by Follistatin. Activin A is induced by inflammatory cytokines and inhibited by glucocorticoids.
- The receptors for Activin A are expressed by many stromal cells, among them fibroblasts, hepatocytes, myometral cells, vascular endothelial cells, and neuronal progenitor cells.
- Ligand Receptor
- Type I receptors ALK4 and ALK7, Type II receptors ActRIIA and ActRIIB.
- Cell Type
- Neural Stem Cells, Hematopoietic stem and progenitors, Embryonic Stem Cells
- Biology Area
- Cell Biology, Neuroscience, Stem Cells, Synaptic Biology
- Molecular Family
- Growth Factors, Cytokines/Chemokines
- Antigen References
1. Schwall RH, et al. 1988. Mol. Endocrinol. 2:1237.
2. Hashimoto M, et al. 1992. J. Biol. Chem. 267:4999.
3. Shav-Tal Y and Zipori D. 2002. Stem Cells 20:493.
4. Dohi T et al. 2005. Gastroenterology 128:411.
5. Tsuchida K, et al. 2008. Endocr. J. 55:11.
6. Djouad F, et al. 2010. Steam Cell Res. Ther. 1:11.
7. Sako D, et al. 2010. J. Biol. Chem. 285:21037.
8. Jones CP, et al. 2012. J. Allergy Clin. Immunol. 129:1000.
- Gene ID
- 3624 View all products for this Gene ID
- View information about Activin A on UniProt.org
- Does specific activity of a recombinant protein vary between lots?
Specific activity will vary for each lot and for the type of experiment that is done to validate it, but all passed lots will have activity within the established ED50 range for the product and we guarantee that our products will have lot-to-lot consistency. Please conduct an experiment-specific validation to find the optimal ED50 for your system.
- Have your recombinants been tested for stability?
Our testing shows that the recombinant proteins are able to withstand room temperature for a week without losing activity. In addition the recombinant proteins were also found to withstand four cycles of freeze and thaw without losing activity.
- How do you convert activity as an ED50 in ng/ml to a specific activity in Units/mg?
- Use formula Specific activity (Units/mg) = 10e6/ ED50 (ng/mL)
- How does the activity of your recombinant proteins compare to competitors?
We quality control each and every lot of recombinant protein. Not only do we check its bioactivity, but we also compare it against other commercially available recombinant proteins. We make sure each recombinant protein’s activity is at least as good as or better than the competition’s. In order to provide you with the best possible product, we ensure that our testing process is rigorous and thorough. If you’re curious and eager to make the switch to BioLegend recombinants, contact your sales representative today!
- What is the specific activity or ED50 of my recombinant protein?
The specific activity range of the protein is indicated on the product datasheets. Because the exact activity values on a per unit basis can largely fluctuate depending on a number of factors, including the nature of the assay, cell density, age of cells/passage number, culture media used, and end user technique, the specific activity is best defined as a range and we guarantee the specific activity of all our lots will be within the range indicated on the datasheet. Please note this only applies to recombinants labeled for use in bioassays. ELISA standard recombinant proteins are not recommended for bioassay usage as they are not tested for these applications.