Vascular Endothelial Growth Factor-121, Recombinant, Human (VEGF-121)
|Molecular Biology||Storage: -20°CShipping: Blue Ice|
Vascular endothelial growth factor-A was originally isolated from tumor cells and referred to as Tumor Angiogenesis Factor or Vascular Permeability Factor. Although expressed at high levels in certain tumor-derived cells it is produced by a wide variety of cell types. In addition to stimulating vascular growth and vascular permeability it may play a role in stimulating Vasolidation via nitric oxide-dependent pathways. Alternative splicing of the mRNA for VEGF-A results in several isoforms of the protein being produced. Rat and bovine VEGF are one amino acid shorter than the human factor, and the bovine and human sequences show a homology of 95 percent. In contrast to other factors mitogenic for endothelial cells such as FGF-1 , FGF-2 and PDGF, VEGF is synthesized as a precursor containing a typical hydrophobic secretory signal sequence of 26 amino acids. Glycosylation is not required for efficient secretion of VEGF.
Recombinant Human VEGF-121 produced in insect cells is a double, non-glycosylated, polypeptide chain containing 121 amino acids and having a molecular mass of 28423 Dalton. VEGF121 circulates more freely than other VEGF forms, which bind more tightly with vascular heparin sulfates. Recombinant Human VEGF-121 is purified by proprietary chromatographic techniques.
Dimers and Aggregates:
Less than 1% as determined by silver-stained SDS-PAGE gel analysis.
Recombinant Human VEGF-121 is fully biologically active when compared to standards. Determined by the dose-dependent stimulation of the proliferation of human umbilical vein endothelial cells (HUVEC) using a concentration range of 0.2-0.4 ng/ml, corresponding to a Specific Activity of 5 x 105 IU/mg.
0.1ng/ug (IEU/ug) of VEGF 121.
Protein quantitation was carried out by two independent methods:
1. UV spectroscopy at 280 nm.
2. Analysis by RP-HPLC, using a calibrated solution of VEGF-121 as a Reference Standard.
It is recommended to reconstitute the lyophilized Human VEGF-121 in sterile 18M -cm H2O not less than 100µg/ml, which can then be further diluted to other aqueous solutions.
Lyophilized Recombinant VEGF-121 although stable at room temperature for 3 weeks, should be stored desiccated below -180C. Upon reconstitution VEGF-121 should be stored at 40C between 2-7 days and for future use below -180C. For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA). Please prevent freeze-thaw cycles.
Source: Sf9 insect cells
Purity: 90% as determined by:
(a) Analysis by RP-HPLC.
(b) Anion-exchange FPLC.
(c) Analysis by reducing and non-reducing SDS-PAGE Silver Stained gel.
Form: Supplied as a lyophilized powder without additives.
Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.