Energy-dependent accumulation of iron by isolated rat liver mitochondria. II. Relationship to the active transport of Ca2+

摘要: Abstract 1. Rat liver mitochondria isolated in sucrose- N -2-hydroxyethylpiperazine- ′-2-ethanesulphonic acid medium possess high- and low-affinity binding sites of iron when 59 Fe(III)-sucrose is used as a soluble stable model complex. At pH 7.4 the bind about 60 nmoles per mg protein with K m ′ ≈ 0.4 mM. The high-affinity 10 30 μ M completely inhibited by uncoupler carbonyl cyanide- -chlorophenylhydrazone. 2. When were incubated Fe(III)-[ 14 C]sucrose substrate, complex accumulated an energy-independent mechanism. Thus, largely due to complex(es). 3. energy-dependent accumulation La 3+ , ruthenium red, hexaminecobalt(III) chloride sulphydryl reagents, i.e. reagents which all inhibit Ca 2+ uptake. Furthermore, inhibits competitive manner ( i = 115 M) without affecting accumulation. These results suggest that mechanism loading similar .