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Recombinant FGF2-G3 (154aa) protein

QK053

Brand: Qkine

Recombinant FGF2-G3 (FGF2-STAB®) protein is a thermostable engineered form of FGF-2 (bFGF). Qk053 is the 154 aa mature domain of FGF-2 (Qk027) with nine amino acid substitutions to enhance stability without impacting bioactivity developed by Dvorak et al. 2018. This increases the functional half-life of the protein from <10 h (wild-type) to >7 days (FGF2-G3).

Recombinant FGF2-G3 is used in B8 media (Kuo et al. 2019) for weekend free, high homogeneity induced pluripotent stem cell culture. FGF2-G3 also has applications in chemically defined stem cell and organoid culture media, and cultured meat media development.

High purity 17 kDa bioactive FGF2-G3 protein, animal origin-free (AOF), carrier protein-free and tag free.

Currency: 

Product name Catalog number Pack size Price Price (USD) Price (GBP) Price (EUR)
Recombinant FGF2-G3 protein, 50 µg QK053-0050 50 µg (select above) $ 185.00 £ 140.00 € 164.00
Recombinant FGF2-G3 protein, 100 µg QK053-0100 100 µg (select above) $ 280.00 £ 210.00 € 246.00
Recombinant FGF2-G3 protein, 500 µg QK053-0500 500 µg (select above) $ 725.00 £ 540.00 € 631.00
Recombinant FGF2-G3 protein, 1000 µg QK053-1000 1000 µg (select above) $ 1,050.00 £ 800.00 € 935.00

Note: prices shown do not include shipping and handling charges.

Qkine company name and logo are the property of Qkine Ltd. UK.

Alternative protein names
Basic fibroblast growth factor, bFGF, FGF-β, FGF2, Fibroblast growth factor-basic, HBGF-2, FGF2-G3, FGF2-STAB, FGF2-STAB2
Species reactivity
Species neutral

Alternative:

Recombinant FGF-G3 (145 aa) protein (Qk052)

Frequently used together with:

Summary

  • High purity thermostable recombinant FGF2-G3 protein comprising 154 aa form of FGF-2 (Uniprot: P09038) with nine stabilizing amino acid substitutions
  • >98%, by SDS-PAGE quantitative densitometry
  • 17 kDa
  • Expressed in E. coli.
  • Animal origin-free (AOF) and carrier protein-free.
  • Manufactured in Qkine's Cambridge, UK laboratories
  • Lyophilized from Tris/NaCl/CyS/mannitol
  • Resuspend in water at >100 µg/ml, prepare single use aliquots, add carrier protein if desired, store frozen at -20°C (short-term) or -80°C (long-term)
Handling and Storage FAQ

Featured applications

  • Expansion of induced pluripotent, embryonic and mesenchymal stem cells
  • Cell expansion

Bioactivity

Human LIF Qk036 protein bioactivity lot #14293

Recombinant FGF2-G3 activity is determined using the Promega serum response element luciferase reporter assay (*) in transfected HEK293T cells. EC50 = 90 pg/ml (5.2 pM). Cells are treated in triplicate with a serial dilution of FGF2-G3 for 3 hours. Firefly luciferase activity is measured and normalized to the control Renilla luciferase activity. Data from Qk053 lot #104340. *Promega pGL4.33[luc2P/SRE/Hygro] #E1340

 

Purity

Human LIF Qk036 protein purity SDS-PAGE lot #14293

Recombinant FGF2-G3 migrates as a major band at 17 kDa in non-reducing (NR) conditions. The higher molecular weight minor band is the dimeric form. Upon reduction (R), only the 17 kDa band is visible. No contaminating protein bands are present. Purified recombinant protein (3 µg) was resolved using 15% w/v SDS-PAGE in reduced (+β-mercaptothanol, R) and non-reduced (NR) conditions and stained with Coomassie Brilliant Blue R250. Data from Qk053 batch #104340.

Further quality assays

  • Mass spectrometry: single species with expected mass
  • Analytical reversed-phase: single sharp peak
  • Endotoxin: <0.005 EU/μg protein (below level of detection)
  • Recovery from stock vial >95%

Wild-type FGF-2 (Qk027) and FGF2-G3 (Qk053) have equivalent bioactivity

FGF2-G3 activity is determined using the Promega serum response element luciferase reporter assay (*) in transfected HEK293T cells. Cells are treated in triplicate with a serial dilution of FGF2-G3 for 3 hours. Firefly luciferase activity is measured and normalized to the control Renilla luciferase activity. *Promega pGL4.33[luc2P/SRE/Hygro] #E1340

‘After a long day running samples and analysing data, it was very exciting to see just how stable the FGF2-G3 proteins were. They clearly have more endurance than me!’

– Kerry, Qkine Senior Scientist

Hyperstable FGF2-G3 retains activity after pre-incubation with conditioned media at 37°C

FGF2-G3 (Qk053)            WT FGF2 (Qk027)

WT FGF-2 (Qk027) and FGF2-G3 (Qk053) were diluted in conditioned media and incubated at 37oC. Samples were taken at 24 h intervals and FGF-2 activity was assayed in triplicate using the Promega serum response element luciferase reporter assay (*) in transfected HEK293T cells. Firefly luciferase activity was normalized to the control Renilla luciferase activity (F/R).

Protein background

FGF-2 (also known as basic FGF or bFGF) is an essential growth factor for maintaining human embryonic stem cell (hESC) and induced pluripotency stem cell (iPSC) pluripotency in feeder-free and chemically defined stem cell media. It is a core component of widely adopted media including mTESR (Ludwig et al. 2006), StemPRO (Wang et al. 2007) and E8 (Chen et al. 2011). However, FGF-2 is inherently unstable and prone to proteolytic degradation and aggregation. This fundamental biochemical instability, and therefore low half-life in culture media (<10 h), is an important contribution to the need for frequent media changes and challenges in improving homogeneity during stem cell proliferation and subsequent differentiation.

To improve the stability of FGF-2 for stem cell media and regenerative medicine applications, Dvorak and colleagues at Masaryk University used computer-assisted protein engineering to identify an optimal set of nine amino acid substitutions that stabilize FGF-2. These substitutions were designed to avoid structural changes to the FGF receptor 1 (FGFR1) and FGF receptor 2 (FGFR2) binding interface. This thermostable FGF-2 is known as FGF2-G3, or FGF2-STAB® (Dvorak et al. 2017). The biological activity of wild-type FGF-2 is <50% after 10h incubation with conditioned media. In contrast, no reduction in FGF2-G3 biological activity is observed after >7 days incubation with conditioned media at 37°C. Both FGF2-G3 and wild-type FGF-2 maintain hESC pluripotency and expression of pluripotency markers Oct-4 and nanog with equivalent efficacy (Dvorak et al. 2017).

In 2020, Paul Burridge and colleagues at Northwestern University, Chicago, published a protocol for B8 media. This iPSC maintenance media uses thermostable FGF2-G3, along with optimization of media component concentration and composition to reduce media cost and facilitate weekend-free stem cell culture regimes (Kuo et al. 2020 and updated in Lyra-Leite et al. 2020).

To manufacture and provide recombinant FGF2-G3 for stem cell culture, including use in B8 media and emerging applications such as cellular agriculture, Qkine has licensed the patented FGF2-G3 technology from Enantis/Masaryk University. We have combined the excellent science behind the FGF2-G3 technology with our protein manufacture expertise to provide gold standard protein for use in cell culture media. We have removed His tags present in the academic forms of the protein for FGF2-G3 (Qk053), as these may cause issues for scientists looking to translate discoveries to clinical or scale-up applications, and introduce unnecessary scientific uncertainties.

Two forms of FGF-2 are used frequently in stem cell culture: 145 aa (Qk025) and 154 aa (Qk027).

The 9 aa pro-segment of FGF2 present in the 154 aa FGF-2 is not required for biological activity and is thought to have roles in the localization of FGF-2 in vivo.

We wanted to allow scientists to compare directly with their existing FGF-2, so we introduced the nine amino acid substitutions into the 145 aa form of FGF-2 to make Qk052 FGF2-G3 (145 aa). The EC50 of the two forms of FGF2-G3 are 90 pg/ml and 47 pg/ml for the 154 aa and 145 aa forms respectively. As observed previously, the half-life is extended to >3 days.

FGF2-G3 – Key papers

Dvorak et al. 2018

Development of FGF2-G3 form using AI
View publication

 Kuo et al. 2020

Development of B8 media – low cost, weekend free iPSC media
View publication

 Beltran-Rendon, C., Price, C. J. et al. 2024

Modeling the selective growth advantage of genetically variant human pluripotent stem cells to identify opportunities for manufacturing process control
View publication

 Koledova et al. 2019

Assessment of FGF2-G3 stability and signalling
View publication

 Benington et al. 2020

Nice review of FGF2 stability and stabilisation methods
View publication

 Lyra-Leite et al. 2021

Updated protocol for B8 media
View publication

 van Bree, N., Oppelt, A. et al. 2024

Development of an orthotopic medulloblastoma zebrafish model for rapid drug testing
View publication

Publications using FGF2-G3 protein (Qk053)

Modeling the selective growth advantage of genetically variant human pluripotent stem cells to identify opportunities for manufacturing process control.
In Cytotherapy in April 2024 by Beltran-Rendon, C., Price, C. J. et al.
View publication

Ephrin-A2 and Phosphoantigen-Mediated Selective Killing of Medulloblastoma by γδ T Cells Preserves Neuronal and Stem Cell Integrity
bioRxiv preprint on 13 October 2024 by Boutin, L. et al.
View publication

mTOR activity paces human blastocyst stage developmental progression
In Cell on 26 September 2024 by Lyer, D. P., Khoei, H. H. et al.
View publication

A chemically defined and xeno-free hydrogel system for regenerative medicine.
Preprint on 2 June 2024 by Ong, J. Gibbons, G., Siang, L. Y. et al.
View publication

Feeder-free culture of human pluripotent stem cells drives MDM4-mediated gain of chromosome 1q.
In Stem Cell Reports on 13 August 2024 by Stavish, D. et al.
View publication

Cytogenetic resource enables mechanistic resolution of changing trends in human pluripotent stem cell aberrations linked to feeder-free culture.
Preprint on 21 September 2023 by Stavish, D. et al.
View publication

Refined home-brew media for cost-effective, weekend-free hiPSC culture and genetic engineering.
In Open Research Europe 2024 by Truszkowski, L., Bottini, S., Bianchi, S. et al.
View publication

Development of an orthotopic medulloblastoma zebrafish model for rapid drug testing.
Preprint on 121 February 2024 by van Bree, N., Oppelt, A. et al.
View publication