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Recombinant human FGF-8a protein (Qk059)
Fibroblast growth factor 8a (FGF-8a) is a member of the FGF family and plays a key role in the regulation of embryogenesis, cellular proliferation, differentiation, and migration. FGF-8a is often used for the differentiation of induced pluripotent stem cells, embryonic stem cells, and neural stem cells.
FGF-8a is a spliced form of FGF-8, a heparin-binding protein that targets mammary and non-mammary cells expressing the FGF receptors. A 21.3 kDa highly pure, bioactive recombinant protein produced in an animal-free expression system. This protein is animal-origin free (AOF), carrier protein-free, tag-free, and non-glycosylated to ensure a pure homogenous protein with exceptional lot-to-lot consistency. Qk059 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-8a protein (Uniprot: P55075-2)
>98%, by SDS-PAGE quantitative densitometry
- 21.3 kDa
- Expressed in E. coli
Animal-origin free (AOF) and carrier protein-free
- Manufactured in our Cambridge, UK laboratories
Lyophilized from HEPES/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
- Neurite outgrowth from spiral ganglion neurons
- Differentiation of ESCs and iPSCs into dopaminergic (DA) neurons
- Morphogenesis of mid-hindbrain
- Neuronal induction in neural development
AIGF, AIGFKAL6, Androgen-induced growth factor, FGF8, FGF-8, Fibroblast Growth Factor – 8, HBGF-8, Heparin Binding Growth Factor – 8, MGC149376
human
species similarity:
mouse – 100%
rat – 100%
porcine – 100%
bovine – 100%
Bioactivity
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FGF-8a activity is determined using the Promega serum response element luciferase reporter assay (*) in HEK293T cells. EC50 = 110 ng/ml (5.2 nM). Cells are treated in triplicate with a serial dilution of FGF-8a in the presence of 10 µg/ml heparin for 3 hours. Firefly luciferase activity is measured and normalized to the control Renilla luciferase activity. Data from Qk059 lot #104406. *Promega pGL4.33[luc2P/SRE/Hygro] #E1340
Purity
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FGF-8a (Qk059) migrates as a single band at 21.3 kDa in non-reducing (NR) conditions and upon reduction (R). 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 Qk059 batch #104412.
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-8a is more biologically active than mammalian-origin comparable alternative
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Quantitative luciferase assay with Qkine FGF-8a (Qk059, green) and alternative supplier FGF-8a (Supplier B, black). Cells were treated in triplicate with a serial dilution of FGF-8a for 3 hours in the presence of 10 µg/ml heparin. Firefly luciferase activity was measured and normalized to control Renilla luciferase activity.
Differentiation of induced pluripotent stem cells (iPSCs) into dopaminergic neurons
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Day 35 differentiated mature dopaminergic neurons (A, scale bar = 750 µM, B, scale bar = 300 µM).
Protein background
FGF-8a 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 spliced 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-8a, a monomeric protein has a molecular weight of 21.3kDa with 182 amino acid (aa) residues covering the signal sequence domain, N-terminal domain, FGF domain and proline-rich C terminal sequence [5]. Its three-dimensional structure is composed of two antiparallel beta-sheet and several alpha-helices. The protein contains a conserved heparin-binding domain that is essential for its biological activity. This domain binds to heparin sulfate proteoglycans on the cell surface and helps to localize FGF8a to its target cells.
FGF-8, including the spliced forms, functions by binding the FGF receptors (FGFR) to activate the Ras/MAPK signaling 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 [6-8].
Functionally, FGF-8a 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 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-8a is required for morphogenesis and neurogenesis [13]. 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 [10].
Furthermore, FGF-8a has been used to generate embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs)-derived ventral midbrain dopaminergic (DA) neurons [14]. FGF-8a has also been shown to play a role in neuronal induction during neural development and neurite outgrowth from spiral ganglion neurons in vitro [15-16].
Whilst there is 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 [17-19]. 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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