Activin A2019-05-30T10:04:38+00:00

Recombinant human Activin A (ActA)

Activin A is a member of the TGFβ superfamily of growth factors involved in stem cell differentiation and maintenance, regulation of embryogenesis, development of the reproductive system, wound healing and regulation of immune responses. The activity of Activin A is regulated by the high-affinity inhibitor, follistatin (1), and inhibins.
Activins are disulphide-linked homo- and heterodimers of four inhibin β chains. The best characterised are Activin A and Activin B, homodimers of inhibin βA and inhibin βB respectively. Activins, like all other members in the TGF-β superfamily, are synthesized as larger precursors consisting of an N-terminal signal peptide, a pro-domain of 250–350 residues and a highly conserved mature domain. The pro-domain, which is cleaved off in the mature protein, has important roles in the biosynthesis, stabilisation, transportation and signalling of the growth factors (2).
Activin A is used for maintenance of pluripotency in many human induced-pluripotent stem cell and human embryonic stem cell lines (3), and to induce stem cell differentiation into endoderm (4) and other cell fates.

Qkine makes two forms of Activin A: 

Qk001 Activin A is the wild-type protein and has been extensively validated and benchmarked against industry standards.  View the results of this analysis and a commentary by Qkine’s founder Marko Hyvonen.

Qk005 Activin A Plus 2.1 incorporates an N-terminal truncation to remove a disulphide-linked extension. This recombinant protein is optimised for extremely consistent high yield with no observed changes in bioactivity compared to the wild-type. This form is particularly suitable for larger scale culture processes.

Alternative protein names: ActA, Activin beta-A chain, Erythroid differentiation protein (EDP), Follicle-Stimulating Hormone (FSH) releasing protein (FRP), INHBA, Inhibin beta A, Inhibin beta 1
Structure of Activin A cytokine

1. Harrington, A. E. et al. Structural basis for the inhibition of activin signalling by follistatin. EMBO J. 25, 1035–1045 (2006).
2. Wang, X., Fischer, G. & Hyvönen, M. Structure and activation of pro-activin A. (2016). doi:10.1038/ncomms12052
3. Pauklin, S. & Vallier, L. Activin/Nodal signalling in stem cells. Development 142, 607–19 (2015).
4. D’Amour, K. A. et al. Efficient differentiation of human embryonic stem cells to definitive endoderm. Nat. Biotechnol. 23, 1534–1541 (2005).

Summary: Qk001 mature domain of human activin A (residues 311-426, Uniprot: P08476) expressed in E. coli, refolded and purified to homogeneity. The mature protein is a disulphide-linked dimer.

Form: protein is provided lyophilised from a fully volatile solution without carrier protein.

Molecular mass: ~26 kDa (for the dimer)

Quality testing: all our proteins are made in-house by our scientists.  We take the quality of our proteins very seriously and you can view the full quality testing data for each batch of protein by clicking on the link below

Qk001 ActA batch #011

Activins are very poorly soluble in physiological solutions, so we would recommend following the handling guidance for lyophilised cytokines instructions closely.To minimise loss of protein due to precipitation or adsorption to plastic, we advise storing the recombinant protein at very low pH to before dilution in cell culture media. Low pH will also assist in maintaining the correct disulphide structure of the protein by minimising disulphide bond exchange reactions.

Every effort is made to ensure samples are sterile however we recommend sterile filtering after dilution in media or the final working solution.

Buy online or email orders@qkine.com

Summary: Qk005 engineered mature domain of human activin A (Uniprot: P08476) expressed in E.coli, refolded and purified to homogeneity. This engineered form of Activin A incorporates an N-terminal truncation to remove a disulphide-linked extension. The resulting protein is optimised for extremely consistent high yield with no observed changes in bioactivity compared to the wild-type. This form is particularly suitable for larger scale culture processes. The mature engineered protein is a disulphide-linked dimer.

Form: protein is provided lyophilised from a fully volatile solution without carrier protein.

Molecular mass: ~24 kDa (for the dimer)

Quality testing: all our proteins are made in-house by our scientists.  We take the quality of our proteins very seriously and you can view the full quality testing data for each batch of protein by clicking on the link below

Qk005 ActA+ 2.1 batch #010

Activins are very poorly soluble in physiological solutions, so we would recommend following the handling guidance for lyophilised cytokines instructions closely.To minimise loss of protein due to precipitation or adsorption to plastic, we advise storing the recombinant protein at very low pH to before dilution in cell culture media. Low pH will also assist in maintaining the correct disulphide structure of the protein by minimising disulphide bond exchange reactions.

Every effort is made to ensure samples are sterile however we recommend sterile filtering after dilution in media or the final working solution.

Buy online or email orders@qkine.com

We take the quality of our proteins very seriously

All our proteins are produced in-house by our scientists and we understand the impact on your work if your growth factors and cytokines don't perform as expected.

Please visit this article by our founder, Marko Hyvonen to understand why we think improving growth factor quality will save valuable time and expense.

Qkine quality promise: our growth factors and cytokines work. If they don’t, we give you your money back. Simple as that.

Find out more

Buy online or email orders@qkine.com

  • Mature domain of human activin A (residues 311-426, Uniprot: P08476) expressed in E.coli, refolded and purified to homogeneity. The mature protein is a disulphide linked dimer with a molecular weight of ca. 25 kDa. Protein is provided lyophilised, without carrier protein. Sequence: GLECDGKVNI CCKKQFFVSF KDIGWNDWII APSGYHANYC EGECPSHIAG TSGSSLSFHS TVINHYRMRG HSPFANLKSC CVPTKLRPMS MLYYDDGQNI IKKDIQNMIV EECGCS*
  • Engineered mature domain of human activin A (Uniprot: P08476) expressed in E.coli, refolded and purified to homogeneity. This engineered form of Activin A incorporates an N-terminal truncation to remove a disulphide-linked extension. The resulting protein is optimised for extremely consistent high yield with no observed changes in bioactivity compared to the wild-type. This form is particularly suitable for larger scale culture processes. The mature engineered protein is a disulphide-linked dimer with a molecular weight of 24 kDa.