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Recombinant human FGF-8b protein (Qk057)
Fibroblast growth factor 8b (FGF-8b) is a member of the FGF family involved in the regulation of embryogenesis, cellular proliferation, differentiation, and migration.
FGF-8b is commonly used for the differentiation of induced pluripotent stem cells into neural cell types and brain organoid cultures.
FGF-8b is a spliced form of FGF-8, a heparin-binding protein that targets mammary and non-mammary cells expressing the FGF receptors. A 22.5 kDa highly pure, bioactive recombinant protein produced in an animal origin-free expression system. This protein is carrier-free, tag-free and non-glycosylated to ensure a pure, homogenous protein with exceptional lot-to-lot consistency. Qk057 is suitable for enhanced reproducibility and physiologically relevant cultures.
Orders are typically shipped same or next day (except Friday).
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1000µg will be despatched as 2 x 500µg
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For any questions, please email orders@qkine.com
Summary
High purity human FGF-8b protein (Uniprot: P55075)
>98%, by SDS-PAGE quantitative densitometry
- 22.5 kDa
- Expressed in E. coli
Animal origin-free (AOF) and carrier protein-free
- Manufactured in our Cambridge, UK laboratories
- Lyophilized from HEPES pH 7.5, NaCl, Mannitol
Resuspend in water at >100 µg/ml, prepare single use aliquots, add carrier protein if desired and store frozen at -20°C or -80°C
Featured applications
Generation of iPSC-derived dopaminergic (DA) neurons
Generation of induced neuronal cells from reprogrammed fibroblasts
Generation of iPSC-derived midbrain organoids
Neurite outgrowth from spinal ganglion neurons
AIGF, AIGFKAL6, Androgen-induced growth factor, FGF8, FGF-8, Fibroblast Growth Factor – 8, HBGF-8, Heparin Binding Growth Factor – 8, MGC149376
human, mouse
Bioactivity
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FGF-8b activity is determined using the Promega serum response element luciferase reporter assay (*) in HEK293T cells. EC50 = 4.1 ng/ml (0.18 nM). Cells are treated in triplicate with a serial dilution of FGF-8b for 3 hours. Firefly luciferase activity is measured and normalized to the control Renilla luciferase activity. Data from Qk057 lot #104458. *Promega pGL4.33[luc2P/SRE/Hygro] #E1340
Purity
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FGF-8b (Qk057) migrates as a single band at 22.5 kDa in non-reducing (NR) conditions and upon reduction. 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 Qk057 batch #104458.
Further quality assays
- Mass spectrometry, single species with expected mass
Endotoxin: <0.005 EU/μg protein (below level of detection)
- Recovery from stock vial: >95%
We are a company founded and run by scientists to provide a service and support innovation in stem cell biology and regenerative medicine. All our products are exceptionally high purity, with complete characterisation and bioactivity analysis on every lot.
Qkine animal origin-free FGF-8b produces consistently high bioactivity lot-to-lot
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Qkine FGF-8b (Qk057) protein has exceptional lot-to-lot consistency. Bioactivity was determined using a firefly luciferase reporter assay in stably transfected HEK293T cells. Cells were treated with a serial dilution of independent lots of FGF-8b for 3 hours in triplicate.
Qkine FGF-8b is as biologically active as the comparable alternative supplier protein
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Bioactivity was determined using the Promega serum response element luciferase reporter assay in transfected HEK293T cells. Cells were treated in triplicate with a serial dilution of Qkine FGF-8b (Qk057, green) or an alternative supplier protein (Supplier B, black) for 3 hours. Firefly luciferase activity was measured and normalized to the control Renilla luciferase activity.
Protein background
FGF-8b is a heparin-binding protein and an isoform of FGF-8 belonging to a family of fibroblast growth factors (FGF) [1]. It was originally discovered as an essential growth factor for the androgen-dependent growth of mouse mammary carcinoma cells [2]. In mouse, there are eight sliced protein isoforms of FGF8 (a-h) whereas in humans, there are four alternate spliced protein isoforms namely FGF-8a, FGF-8b, FGF-8e and FGF-8f. These four FGF8 isoforms (a, b, e and f) are highly conserved between humans and mice. Human and murine FGF-8a and FGF-8b show 100% homology [3] whereas there is a 98% identity with human and murine FGF8e and FGF8f [4].
Human FGF-8b, a monomeric protein has a molecular weight of 22.5kDa with 194 amino acid (aa) residues covering the signal sequence domain, N-terminal domain, FGF domain and proline-rich C terminal sequence. Its three-dimensional structure is composed of 12 beta strands arranged in two beta-sheet and short alpha-helices. The protein contains a conserved heparin-binding domain that is essential for its biological activity.
FGF-8, including the spliced forms, work by binding the FGF receptors (FGFR) to activate the Ras/MAPK signalling pathway, a key pathway that contributes to several cellular processes. In general, the FGF family is involved in broad cellular and biological processes including cell proliferation, differentiation, survival and apoptosis [5-8].
Functionally, FGF-8b has been shown to play a major role during prenatal development. It is widely expressed during embryogenesis and is a key player in epithelial-mesenchymal transitions [9]. During gastrulation, it contributes to the organization and induction role and regulates the patterning of organs in the embryos. These organs include the brain, eye, ear, limb and the heart [10-12].
Although, FGF-8 isoforms work in a coordinated and concerted manner, findings have suggested that they also have distinct key roles. FGF-8b has been shown to have the strongest affinity for the receptor and oncogenic capacity. A study using transgenic mice showed FGF-8a expands the midbrain while FGF-8b showed a transformational activity by transforming the midbrain into the cerebellum [13].
FGF-8b and other neurotrophins have been shown to promote neural regeneration. More specifically, FGF-8b has been shown to promote neurite outgrowth in mammalian spiral ganglion neurons (SGN) in vitro [14]. FGF-8b, in combination with Shh, a neurotrophic factor, and transcription factors Ascl1 and Nurr1, has been used to generate induced neuronal cells (pan-neuronal and dopaminergic (DA) neurons) by reprogramming embryonic mouse fibroblasts [15]. Additionally, FGF-8b has been used to generate DA neurons from stem cells, including induced pluripotent stem cells (iPSCs) and dental pulp stem cells [16-17]. More recently, FGF-8b has been used to generate ventral midbrain organoids derived from iPSCs to provide a robust 3D in vitro platform that is suitable for comprehensive DA neuronal studies [18].
Whilst there is a limited expression of FGF-8 and its isoforms in the normal adult, increasing studies have shown the presence of FGF-8 in adult tissues and cells including the reproductive tract, peripheral leukocytes and hematopoietic cells [19-20]. Further functional studies are required to fully delineate the role of FGF-8 and its isoforms in the normal adult.
Our products are for research use only and not for diagnostic or therapeutic use. Products are not for resale.
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