Limitin, also called IFN-ζ, is a secreted interferon (IFN)-like glycoprotein. Limitin has approximately 30% sequence homology with IFN- alpha, IFN- beta , and IFN-ω and binds to the IFN- alpha/ beta receptors. Like IFN- alpha and IFN- beta , limitin has antiproliferative, immunomodulatory, and antiviral properties, it is unique in lacking influence on myeloid and erythroid progenitors. Similar dose requirement between limitin and IFN- alpha was observed for the enhancement of cytotoxic T lymphocyte activity, the augmentation of MHC class I expression, and the growth inhibition of a myelomonocytic leukemia cell line.
Lyophilized protein should be stored at -20˚C, though stable at room temperature for 3 weeks. Reconstituted protein solution can be stored at 4-7˚C for 2-7 days. Aliquots of reconstituted samples are stable at -20˚C for 3 months.