Introduction
The FGFs are a family of over 20 small (approximately 17–26 kDa) secreted peptides. Initial research on these proteins centered around their capacity to promote fibroblast proliferation. This mitogenic activity was facilitated by FGF receptors (FGFRs) 1, 2, or 3. A fourth, closely related tyrosine kinase receptor (FGFR4) exhibited binding affinity for FGFs but did not elicit a mitogenic response.
FGFs influence cellular behavior through at least five distinct subfamilies of high-affinity FGF receptors (FGFRs): FGFR-1, -2, -3, and -4, all possessing intrinsic tyrosine kinase activity and, with the exception of FGFR-4, multiple splice isoforms, and FGFR-5, which lacks an intracellular kinase domain. Accumulating evidence suggests that FGFRs may play a significant role in regulating glucose and lipid homeostasis. Overexpression of a dominant negative form of FGFR-1 in β cells results in diabetes in mice, implying that proper FGF signaling is necessary for normal β cell function and blood glucose maintenance. FGFR-2 appears to be a crucial molecule during pancreatic development. Furthermore, FGFR-4 has been implicated in cholesterol metabolism and bile acid synthesis.
FGF-19 has been shown to induce resistance to diet-induced obesity and insulin desensitization, and to enhance insulin, glucose, and lipid profiles in diabetic rodents. Given that these effects are, at least partially, mediated by observed alterations in metabolic rates, FGF-19 can be considered a regulator of energy expenditure.
FGF-21 is primarily expressed in the liver, but a precise understanding of FGF-21 bioactivity and its mechanism of action has been limited. FGF-21 is a potent activator of glucose uptake in adipocytes, protects animals from diet-induced obesity when overexpressed in transgenic mice, and reduces blood glucose and triglyceride levels when administered therapeutically to diabetic rodents.
Description
Recombinant Mouse Fibroblast Growth Factor -21, produced in E. coli, is a single, non-glycosylated polypeptide chain consisting of 192 amino acids with a molecular weight of 21.2 kDa. The amino acid sequence of the recombinant human FGF21 exhibits 100% homology to the amino acid sequence of Mouse FGF21 without the signal sequence and incorporates a 10 amino acid His tag at the N-terminus.
The purification of FGF-21 is achieved through proprietary chromatographic techniques.
Physical Appearance
White lyophilized powder after filtration.
Formulation
The product is filtered (0.4 μm) and lyophilized from a solution of 20mM TRIS, 20mM NaCl, pH 7.5, at a concentration of 0.5 mg/ml.
Solubility
To prepare a working stock solution, it is recommended to add deionized water to achieve a concentration of approximately 0.5 mg/ml and allow the lyophilized pellet to dissolve completely. Please note that this product is not sterile. Before using it in cell culture, it is essential to filter the product through an appropriate sterile filter. To prevent potential aggregation, add DTT (0.2mM) and NaCl (0.1-0.15M) before freezing.
Stability
Lyophilized Recombinant Mouse FGF-21, while stable at room temperature for 3 weeks, should be stored desiccated at a temperature below -18°C. Upon reconstitution, Fibroblast Growth Factor 21 should be stored at 4°C for 2-7 days and at a temperature below -18°C for future use.
For long-term storage, adding a carrier protein (0.1% HSA or BSA) is recommended.
Avoid repeated freeze-thaw cycles.
Purity
Purity exceeds 95.0% as determined by:
(a) Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) analysis.
(b) SDS-PAGE analysis.
Synonyms
Fibroblast growth factor 21, FGF-21.
Amino Acid Sequence
MKHHHHHHAS AYPIPDSSPL LQFGGQVRQR YLYTDDDQDT EAHLEIREDG TVVGAAHRSP ESLLELKALKPGVIQILGVK ASRFLCQQPD GALYGSPHFD PEACSFRELL LEDGYNVYQS EAHGLPLRLP QKDSPNQDATSWGPVRFLPM PGLLHEPQDQ AGFLPPEPPD VGSSDPLSMV EPLQGRSPSY AS.
