描述人类和小鼠PMP20酶蛋白质具有体外抗氧化活性。
文章的细节
-
引用
复制到剪贴板 -
山下式H,亚伯、江、伦敦R, Van Veldhoven PP、Subramani年代,罗杰斯RA, H
描述人类和小鼠PMP20酶蛋白质具有体外抗氧化活性。
生物化学杂志。1999年10月15日,274 (42):29897 - 904。
- PubMed ID
-
10514471 (在PubMed]
- 文摘
-
我们有孤立的互补编码人类和小鼠同系物的酵母蛋白质,酶称为膜蛋白- 20 (PMP20)。比较人类(HsPMP20)的氨基酸序列和鼠标(MmPMP20) PMP20蛋白质显示高度的身份(93%),而与酵母念珠菌boidinii PMP20A和PMP20B (CbPMP20A和CbPMP20B)较少(30%的身份)。HsPMP20和MmPMP20缺乏跨膜区域,CbPMP20A CbPMP20B。HsPMP20 mRNA表达很低在人类胎儿组织,特别是在大脑。在成人组织,HsPMP20 mRNA表达在大多数组织测试。HsPMP20和MmPMP20包含c端三肽序列Ser-Gln-Leu (SQL),类似于过氧化物酶病目标信号1用于蛋白导入过氧化物酶体。HsPMP20酶直接绑定到人类目标信号1受体,HsPEX5。突变分析表明,c端三肽序列,SQL, HsPEX5 HsPMP20对于其绑定是必要的。海拉细胞亚细胞分离,表达epitope-tagged PMP20,表明HsPMP20是本地化在细胞质颗粒含有过氧化物酶体的一部分。Double-staining免疫荧光研究显示colocalization HsPMP20和硫解酶,一种善意的酶蛋白。 The amino acid sequence alignment of HsPMP20, MmPMP20, CbPMP20A, and CbPMP20B displayed high similarity to thiol-specific antioxidant proteins. HsPMP20 exerted an inhibitory effect on the inactivation of glutamine synthetase in the thiol metal-catalyzed oxidation system but not in the nonthiol metal-catalyzed oxidation system, suggesting that HsPMP20 possesses thiol-specific antioxidant activity. In addition, HsPMP20 removed hydrogen peroxide by its thiol-peroxidase activity. These results indicate that HsPMP20 is imported into the peroxisomal matrix via PEX5p and may work to protect peroxisomal proteins against oxidative stress. Because some portion of PMP20 might also be present in the cytosol, HsPMP20 may also have a protective effect in the cytoplasm.