Iron requirement for isolated rat liver mitochondrial protein synthesis

Abstract

Isolated rat liver mitochondrial protein synthesis was severly inhibited by α,α-dipyridyl (a ferrous iron-chelating agent), chloramphenicol and hemin (10 −7 M or greater). In contrast, γ,γ-dipyridyl (a non-iron-chelating analogue of α,α-dipyridyl), cycloheximide and lower concentrations of hemin were non-inhibitory. The inhibitory action of α,α-dipyridyl was reversed by addition of Fe(NH 4) 2(SO 4) 2 while ZnCl 2, CuCl 2 and CoCl 2 were ineffective. Hemin, however, did not protect against the α,α-dipyridyl inhibition of mitochondrial protein synthesis. These results indicate that ferrous iron is required for mitochondrial protein synthesis and suggests that it is through a mechanism independent of hemin concentration.