Iron oxidation and hydrolysis reactions of a novel ferritin from Listeria innocua.
Iron oxidation and hydrolysis reactions of a novel ferritin from Listeria innocua.
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来自无害李斯特菌的新型铁蛋白的铁氧化和水解反应。
DOI：
10.1042/bj3490783
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Chasteen,ND
中科院分区：
文献类型：
--
作者：
Yang,X;Chiancone,E;Stefanini,S;Ilari,A;Chasteen,ND
铁在无害李斯特菌（Listeria innocua）的12亚基铁蛋白中的沉积过程分为三个阶段：快速的第一阶段，Fe ~（2+）与载脂蛋白PZ结合，反应过程为2Fe ~（2+）+PZ→ [Fe ~（2-P）]Z+2+ 2 H ~+，其中[Fe ~（2-P）]Z+2代表在蛋白质的12个铁氧化酶中心形成的双核铁（II）络合物;第二相对应于该假定络合物的氧化，即[Fe 2-P]Z+2+ 1/2 O2→ [Fe 2 O-P]Z+2 H +;以及第三阶段的铁（II）氧化/矿化，即4Fe 2 ++O2+ 8H 2 O → 8 FeOOH（s）+8H+[其中FeOOH（s）表示从溶液中沉淀的水合氧化铁矿物]，当铁的加入量超过24 Fe 2 +/蛋白质时会发生这种情况。与其它铁蛋白相比，L.无害铁蛋白比氧化/矿化反应进行得更慢。水是12亚基中分子氧还原的最终产物。无害铁蛋白（目前的工作）和24亚基大肠杆菌细菌铁蛋白，而H2 O2产生的24亚基哺乳动物铁蛋白。这种差异的可能原因进行了讨论。
Iron deposition in the unusual 12-subunit ferritin from the bacteriumListeria innocuaproceeds in three phases: a rapid first phase in which Fe2+binds to the apoprotein, PZof chargeZ, according to the postulated reaction 2Fe2++PZ→ [Fe2–P]Z+2+2H+, where [Fe2–P]Z+2represents a dinuclear iron(II) complex formed at each of the 12 ferroxidase centres of the protein; a second phase corresponding to oxidation of this putative complex, i.e. [Fe2–P]Z+2+½O2→ [Fe2O–P]Z+2H+; and a third phase of iron(II) oxidation/mineralization, i.e. 4Fe2++O2+8H2O → 8FeOOH(s)+8H+[where FeOOH(s)represents the hydrous ferric oxide mineral that precipitates from the solution], which occurs when iron is added in excess of 24Fe2+/protein. In contrast with other ferritins, the ferroxidation reaction inL. innocuaferritin proceeds more slowly than the oxidation/mineralization reaction. Water is the final product of dioxygen reduction in the 12-subunitL. innocuaferritin (the present work) and in the 24-subunitEscherichia colibacterioferritin, whereas H2O2is produced in 24-subunit mammalian ferritins. Possible reasons for this difference are discussed.