Comparison of ornithine decarboxylase from rat liver, rat hepatoma and mouse kidney.
Comparison of ornithine decarboxylase from rat liver, rat hepatoma and mouse kidney.
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大鼠肝脏、大鼠肝癌和小鼠肾脏的鸟氨酸脱羧酶的比较。
DOI：
10.1042/bj2260577
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Pegg,AE
中科院分区：
文献类型：
--
作者：
Seely,JE;Persson,L;Sertich,GJ;Pegg,AE
比较了从Morris肝癌7777、硫代乙酰胺处理的大鼠肝脏和雄激素刺激的小鼠肾脏中分离的鸟氨酸脱羧酶。平行纯化每个来源的酶，并研究它们的大小，等电点，与单克隆抗体或单特异性兔抗血清的相互作用，以鸟氨酸脱羧酶，和率inactivationin体外。小鼠肾脏，这是一个特别丰富的来源，雄激素诱导后的鸟氨酸脱羧酶，含有两种不同形式的酶略有不同的等电点，但不是在先生。这两种形式有一个快速的周转率，几乎所有的免疫反应性鸟氨酸脱羧酶蛋白在4小时内蛋白质合成被抑制后丢失。在硫代乙酰胺处理的大鼠肝脏和Morris肝癌7777中发现只有一种形式的鸟氨酸脱羧酶。大鼠肝脏和肝癌鸟氨酸脱羧酶蛋白之间没有差异，但大鼠的鸟氨酸脱羧酶可以从小鼠肾脏的鸟氨酸脱羧酶的双向凝胶电泳分离。大鼠蛋白质略小，并且具有略高的酸性等电点。在微粒体系统中体外鸟氨酸脱羧酶失活的研究[Zuretti & Gravela（1983）Biochim. Biophys. Acta 742，269-277]显示，来自大鼠肝脏和肝癌7777以及小鼠肾脏的酶以相同的速率失活。这种失活不是由于酶蛋白质的降解，但可能与由于缺乏硫醇还原剂而形成无活性形式有关。用1，3-二氨基丙烷处理，已知其引起体内鸟氨酸脱羧酶降解速率的增加[Seely & Pegg（1983）Biochem.J.216，701-717]，但不刺激微粒体提取物的失活，表明该系统不对应于体内酶分解的限速步骤。
Comparisons were made of ornithine decarboxylase isolated from Morris hepatoma 7777, thioacetamide-treated rat liver and androgen-stimulated mouse kidney. The enzymes from each source were purified in parallel and their size, isoelectric point, interaction with a monoclonal antibody or a monospecific rabbit antiserum to ornithine decarboxylase, and rates of inactivationin vitro, were studied. Mouse kidney, which is a particularly rich source of ornithine decarboxylase after androgen induction, contained two distinct forms of the enzyme which differed slightly in isoelectric point, but not in Mr. Both forms had a rapid rate of turnover, and virtually all immunoreactive ornithine decarboxylase protein was lost within 4h after protein synthesis was inhibited. Only one form of ornithine decarboxylase was found in thioacetamide-treated rat liver and Morris hepatoma 7777. No differences between the rat liver and hepatoma ornithine decarboxylase protein were found, but the rat ornithine decarboxylase could be separated from the mouse kidney ornithine decarboxylase by two-dimensional gel electrophoresis. The rat protein was slightly smaller and had a slightly more acid isoelectric point. Studies of the inactivation of ornithine decarboxylasein vitroin a microsomal system [Zuretti & Gravela (1983) Biochim. Biophys. Acta 742, 269-277] showed that the enzymes from rat liver and hepatoma 7777 and mouse kidney were inactivated at the same rate. This inactivation was not due to degradation of the enzyme protein, but was probably related to the formation of inactive forms owing to the absence of thiol-reducing agents. Treatment with 1,3-diaminopropane, which is known to cause an increase in the rate of degradation of ornithine decarboxylasein vivo[Seely & Pegg (1983) Biochem. J. 216, 701-717] did not stimulate inactivation by microsomal extracts, indicating that this system does not correspond to the rate-limiting step of enzyme breakdownin vivo.