SUPPRESSION OF CELL-GROWTH BY HEAVY-CHAIN FERRITIN

While producing recombinant rat liver H and L chain ferritin homopolym ers using the baculovirus expression system, we noticed that rat liver H chain ferritin, but not L chain ferritin, had a suppressive effect on the growth of Spodoptera frugiperda (Sf-21) cells. Suppression was observed immediately after infection with recombinant H chain ferritin baculovirus prepared from lysed infected cells, Immediate suppression was observed when purified with either recombinant H chain apoferriti n or various holoferritins (loaded with 1,970 +/- 50 or 2,520 +/- 90 a toms of iron/ ferritin) indicating that suppression was not due to seq uestration of iron required for cell growth, Suppression by H chain fe rritin was also observed upon attempting to express the protein in Esc herichia coli. Strategies for expression of recombinant rat liver H an d L ferritin homopolymers in both prokaryotic and eukaryotic expressio n systems were developed, (C) 1998 Academic Press.