Peroxisomes and reactive oxygen species, a lasting challenge
Peroxisomes and reactive oxygen species, a lasting challenge
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DOI：
10.1007/s00418-009-0563-7
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发表时间：
2009-04-01
影响因子：
2.3
通讯作者：
Voelkl, Alfred
中科院分区：
文献类型：
--
作者：
Angermueller, Sabine;Islinger, Markus;Voelkl, Alfred
过氧化物酶的产生和清除过氧化氢的酶使过氧化物体(PO)成为氧代谢的关键细胞器。过氧化氢酶是过氧化氢酶的经典标志酶，具有过氧化氢和过氧化氢的双重活性。后者负责3，3‘-二氨基联苯胺的染色，极大地方便了细胞器的可视化，促进了PO的进一步研究。D-氨基酸氧化酶催化D-氨基酸的氧化脱氨反应具有严格的立体专一性。该酶在肾脏的活性明显高于肝脏，在门静脉周围的活性明显高于中心周围的大鼠肝细胞。这些组织中的过氧化物体不仅在相邻细胞内，甚至在同一细胞内，其酶活性和蛋白质浓度也不同。此外，该酶似乎优先集中在过氧体基质隔室的中心区域。尿酸氧化酶是一种催化尿酸酸氧化为尿囊素的CuProtein蛋白，它局限于过氧化体核心，而在人类PO中是缺乏的。最近的实验表明，大鼠肝细胞内的核仁似乎与尿酸氧化酶产生的过氧化氢释放到周围细胞质的过氧化物体膜密切相关。黄嘌呤氧化酶专门定位于核心区，氧化黄嘌呤，从而产生过氧化氢和O-2(-)自由基。后者被CuZn超氧化物歧化酶转化为O-2和H_2O_2，最近被证明是一种真正的过氧化物体蛋白。
Oxidases generating and enzymes scavenging H2O2 predestine peroxisomes (PO) to a pivotal organelle in oxygen metabolism. Catalase, the classical marker enzyme of PO, exhibits both catalatic and peroxidatic activity. The latter is responsible for the staining with 3,3'-diamino-benzidine, which greatly facilitated the visualization of the organelle and promoted further studies on PO. d-Amino acid oxidase catalyzes with strict stereospecificity the oxidative deamination of d-amino acids. The oxidase is significantly more active in the kidney than in liver and more in periportal than pericentral rat hepatocytes. Peroxisomes in these tissues differ in their enzyme activity and protein concentration not only in adjacent cells but even within the same one. Moreover, the enzyme appears preferentially concentrated in the central region of the peroxisomal matrix compartment. Urate oxidase, a cuproprotein catalyzing the oxidation of urate to allantoin, is confined to the peroxisomal core, yet is lacking in human PO. Recent experiments revealed that cores in rat hepatocytes appear in close association with the peroxisomal membrane releasing H2O2 generated by urate oxidase to the surrounding cytoplasma. Xanthine oxidase is exclusively located to cores, oxidizes xanthine thereby generating H2O2 and O-2 (-) radicals. The latter are converted to O-2 and H2O2 by CuZn superoxide dismutase, which has been shown recently to be a bona fide peroxisomal protein.