The shelf life is related to many factors, storage state, buffer ingredients, storage temperature and the stability of the protein itself. Generally, the shelf life of liquid form is 6 months at -20°C/-80°C. The shelf life of lyophilized form is 12 months at -20°C/-80°C.
Repeated freezing and thawing is not recommended. Store working aliquots at 4°C for up to one week.
Acts to keep host cells in a proliferation-competent state upon differentiation. Enhances host epidermal growth factor receptor (EGFR) activation after stimulation by EGF by inhibiting EGFR internalization. Induces a redistribution of host caveolin-1 and glycosphingolipid (ganglioside GM1) components of lipid rafts to the plasma membrane. Since GM1s inhibit cytotoxic T-lymphocytes, block immune synapse formation, and enhance proliferative signaling by the EGFR, E5 may enhance immune evasion and cell proliferation via a common mechanism. E5 also alters endosomal pH by interacting with the vacuolar H+-ATPase, which is a proton pump responsible for acidifying cellular organelles. Additionally, E5 prevents transport of the major histocompatibility class I to the cell surface and retains the complex in the Golgi apparatus.