Co-purification of mitochondrial HSP70 and mature protein disulfide isomerase with a functional rat kidney high-M(r) cysteine S-conjugate beta-lyase.
Co-purification of mitochondrial HSP70 and mature protein disulfide isomerase with a functional rat kidney high-M(r) cysteine S-conjugate beta-lyase.
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线粒体 HSP70 和成熟蛋白质二硫键异构酶与功能性大鼠肾高 M(r) 半胱氨酸 S-缀合物 β-裂合酶的共纯化。
DOI：
10.1016/s0006-2952(01)00802-4
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发表时间：
2001
影响因子：
5.8
通讯作者：
Bruschi,SA
中科院分区：
文献类型：
--
作者：
Cooper,AJ;Wang,J;Gartner,CA;Bruschi,SA
S-（1，1，2，2-四氟乙基）-1-半胱氨酸（TFEC，TPEC的半胱氨酸S-缀合物）是肾毒性卤代半胱氨酸S-缀合物的实例。毒性部分由半胱氨酸S-缀合物β-裂解酶催化的TFEC转化为硫代酰化片段以及丙酮酸盐和氨的相关产生引起。在本研究中，我们已经证明大鼠肾匀浆含有至少三种能够催化半胱氨酸S-缀合物β-裂解酶与TFEC反应的酶组分。这些馏分之一含有高分子裂解酶。至少有两种蛋白质与这种高Mr复合物共纯化。N-末端分析（15个循环）显示，较小的物种是成熟蛋白质二硫键异构酶（Mr 54，200），其中24个氨基酸的内质网信号肽已被去除。内部氨基酸测序（15个循环）显示，较大的物种是线粒体HSP 70（mtHSP 70; Mr为75，000）。本发明的发现为先前的观察提供了解释，即当大鼠注射TFEC时，肾线粒体中的mtHSP 70被严重硫代酰化（Reichi等人，J Biol Chem 1993;268：23157-61）。
S-(1,1,2,2-Tetrafluoroethyl)-l-cysteine (TFEC, the cysteine S-conjugate of tetrafluoroethylene) is an example of a nephrotoxic, halogenated cysteine S-conjugate. Toxicity results in part from the cysteine S-conjugate β-lyase(s)-catalyzed conversion of TFEC to a thioacylating fragment with the associated production of pyruvate and ammonia. In the present study, we have demonstrated that rat kidney homogenates contain at least three enzyme fractions that are capable of catalyzing a cysteine S-conjugate β-lyase reaction with TFEC. One of these fractions contains a high-Mrlyase. At least two proteins co-purify with this high-Mrcomplex. N-Terminal analysis (15 cycles) revealed that the smaller species was mature protein disulfide isomerase (Mr∼54,200) from which the 24 amino acid endoplasmic reticulum signal peptide had been removed. Internal amino acid sequencing (15 cycles) revealed that the larger species was mitochondrial HSP70 (mtHSP70; Mr∼75,000). The present findings offer an explanation for the previous observation that mtHSP70 in kidney mitochondria is heavily thioacylated when rats are injected with TFEC (Bruschi et al., J Biol Chem 1993;268:23157–61).