IDI2, a second lsopentenyl diphosphate isomerase in mammals
IDI2, a second lsopentenyl diphosphate isomerase in mammals
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DOI：
10.1074/jbc.m610922200
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发表时间：
2007-03-02
影响因子：
4.8
通讯作者：
Krisans, Skaidrite K.
中科院分区：
文献类型：
--
作者：
Clizbe, Daun B.;Owens, Michelle L.;Krisans, Skaidrite K.
我们最近描述了在人类和小鼠中鉴定出一种新型异戊烯基二磷酸异构酶 IDI2。我们目前的数据表明，在人类中，IDI2 仅在骨骼肌中表达。酿酒酵母中人 IDI2 的表达构建体可以补充 idi1 缺陷型酵母菌株中的异构酶功能。此外，IDI2 具有催化 [C-14]IPP 异构化为 [C-14]DMAPP 的能力。部分纯化的IDI2的酶动力学分析表明，该新型同工酶在pH 8.0时的最大相对比活性为1.2 X 10(-1) +/- 0.3 mu mol min(-1) mg(-1)，K-m(IPP)值为22.8 mu m IPP。 IDI1 和 IDI2 两种同工酶均通过 PTS1 依赖性途径定位于过氧化物酶体。最后，我们的数据表明，IDI2 的调节独立于 IDI1，其机制可能涉及 PPAR α。
We recently described the identification of a novel isopentenyl diphosphate isomerase, IDI2 in humans and mice. Our current data indicate that, in humans, IDI2 is expressed only in skeletal muscle. Expression constructs of human IDI2 in Saccharomyces cerevisiae can complement isomerase function in an idi1-deficient yeast strain. Furthermore, IDI2 has the ability to catalyze the isomerization of [C-14]IPP to [C-14]DMAPP. Enzyme kinetic analysis of partially purified IDI2 demonstrate the novel isozyme has a maximal relative specific activity of 1.2 X 10(-1) +/- 0.3 mu mol min(-1) mg(-1) at pH 8.0 with a K-m(IPP) value of 22.8 mu m IPP. Both isozymes, IDI1 and IDI2 are localized to the peroxisome by a PTS1-dependent pathway. Finally, our data suggest that IDI2 is regulated independently from IDI1, by a mechanism that may involve PPAR alpha.