Lefty-A/TGF-beta 4 Protein, Human (HEK293, His)

Lefty-A/TGF-beta 4 Protein, Human is a secreted protein belonging to the transforming growth factor-beta (TGF-β) family, which plays an important role in the development of human left-right axis. Lefty-A/TGF-beta 4 Protein, Human (HEK293, His) is a recombinant Lefty-A/TGF-β 4 protein expressed by HEK293 with an N-6*His tag^{[1][2][3][4][5]}.

Left-right determination factors (LEFTY) are important members of the TGF-β protein superfamily, including LEFTY-1 and LEFTY-2 in mice, as well as LEFTY-A and LEFTY-B in humans. Lefty-A plays a crucial role in determining the left-right asymmetry of the human organ system. Additionally, Lefty-A is a Nodal signaling inhibitor. In undifferentiated human embryonic stem cells, its high expression is maintained by activating Smad2/3 through the Activin/Nodal pathway, and its expression rapidly decreases during differentiation. Its promoter contains binding sites for FoxH1 and Smad2/3, and there is cross-talk with the Wnt pathway to jointly regulate its expression. In addition, Lefty-A plays an important role in the process of renal fibrosis^{[1][2][3][4][5]}.

Lefty A Protein can inhibit the TGF-β1/Smad pathway to reduce TGF-β1/Smad-mediated apoptosis in renal tubular epithelial cells^[4].

1.Measured by its ability to induce cell death using Mv1Lu mink lung epithelial cells. The ED₅₀ for this effect is 0.9733-2.015 μg/mL. 2.Measured by its ability to induce cell death using Mv1Lu mink lung epithelial cells. The ED₅₀ for this effect is 1.805 μg/mL, corresponding to a specific activity is 554.017 units/mg.

• 
  Measured by its ability to induce cell death using Mv1Lu mink lung epithelial cells. The ED₅₀ for this effect is 0.9733 μg/mL, corresponding to a specific activity is 1.027×10³ units/mg.

Human

HEK293

N-6*His

O00292 (L22-K76) & O00292 (F78-P366)

7044  [NCBI]

LTEEQLLGSLLRQLQLSEVPVLDRADMEKLVIPAHVRAQYVVLLRRSHGDRSRGKHHHHHH&FSQSFREVAGRFLASEASTHLLVFGMEQRLPPNSELVQAVLRLFQEPVPKAALHRHGRLSPRSAQARVTVEWLRVRDDGSNRTSLIDSRLVSVHESGWKAFDVTEAVNFWQQLSRPRQPLLLQVSVQREHLGPLASGAHKLVRFASQGAPAGLGEPQLELHTLDLRDYGAQGDCDPEAPMTEGTRCCRQEMYIDLQGMKWAKNWVLEPPGFLAYECVGTCQQPPEALAFNWPFLGPRQCIASETASLPMIVSIKEGGRTRPQVVSLPNMRVQKCSCASDGALVPRRLQP

45-50 kDa

• 
  Greater than 95% as determined by reducing SDS-PAGE.

Lyophilized powder

Lyophilized from a 0.2 μm filtered solution of 20 mM Histidine-HCl, 4% Sucrose, 4% Mannitol, 0.1% Tween80, pH 6.0 or 20 mM His-HCl, 10% Trehalose, 4% Mannitol, 100 mM NaCl, 0.1% Tween 80, pH 5.5 or PBS, pH 7.0, 8% trehalose.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O.

Stored at -20°C for 2 years from date of receipt. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.

• [1]. Kosaki K, et al. Characterization and mutation analysis of human LEFTY A and LEFTY B, homologues of murine genes implicated in left-right axis development. Am J Hum Genet. 1999 Mar;64(3):712-21.  [Content Brief]

  [2]. Yang YR, et al. LEFTY2 alleviates hepatic stellate cell activation and liver fibrosis by regulating the TGF-β1/Smad3 pathway. Mol Immunol. 2020 Oct;126:31-39.  [Content Brief]

  [3]. Besser D. Expression of nodal, lefty-a, and lefty-B in undifferentiated human embryonic stem cells requires activation of Smad2/3. J Biol Chem. 2004 Oct 22;279(43):45076-84.  [Content Brief]

  [4]. Zheng RP, et al. Lefty A protein inhibits TGF-β1-mediated apoptosis in human renal tubular epithelial cells. Mol Med Rep. 2013 Aug;8(2):621-5.  [Content Brief]

  [5]. Li Y, et al. Lefty A attenuates the TGF-beta1-induced epithelial to mesenchymal transition of human renal proximal epithelial tubular cells. Mol Cell Biochem. 2010 Jun;339(1-2):263-70.  [Content Brief]