FoldHelper-57P (recombinant baculovirus expressing ERp57 and PDI) - 1 mL

FoldHelper™-57P provides for expression of human ERp57 (Acc# NP_005304) and human protein disulfide isomerase (PDI) (Acc# CAA28775.1). ERp57 and PDI are homologous proteins participating in disulfide bond formation and oxidative protein folding in the endoplasmic reticulum (Frand A.R.et al., Trends in Cell Biol., 10: 203-210, 2000). PDI was demonstrated to be efficient in oxidative protein folding in vitro (Weissman, J.S. and Kim P.S., Nature, 365: 185-188, 1993). PDIs have multiple functions and, though most abundant in the ER, it is also found in the cytoplasm (Turano, C., et al., J. Cell. Physiol., 193: 154-163, 2002).

A welcome, albeit unexplained effect of PDI in insect cells infected with recombinant baculoviruses, is that PDI improves longevity of such cells. This cytopathic effect is markedly less pronounced in infected cells expressing a high level of PDI, and such cells survive about 24 hours longer than cells infected with a control virus which does not provide for PDI expression. Similarly, PDI overexpression in mammalian cells resulted in increased longevity and time of recombinant protein production (Kitchin, K and Flickinger, M.C., Biotechnol. Progr., 11: 565-574, 1995).