Romero-Puertas María C, Corpas Francisco J, Sandalio Luisa M, Leterrier Marina, Rodríguez-Serrano María, Del Río Luis A, Palma José M
Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, CSIC, Apartado 419, E-18080 Granada, Spain.
New Phytol. 2006;170(1):43-52. doi: 10.1111/j.1469-8137.2006.01643.x.
The glutathione reductase (GR; EC 1.6.4.2) isozyme present in peroxisomes has been purified for the first time, and its unequivocal localization in these organelles, by immunogold electron microscopy, is reported. The enzyme was purified c. 21-fold with a specific activity of 9523 units mg(-1) protein, and a yield of 44 microg protein kg(-1) leaves was obtained. The subunit size of the peroxisomal GR was 56 kDa and the isoelectric point was 5.4. The enzyme was recognized by a polyclonal antibody raised against total GR from pea (Pisum sativum) leaves. The localization of GR in peroxisomes adds to chloroplasts and mitochondria where GR isozymes are also present, and suggests a multiple targeting of this enzyme to distinct cell compartments depending on the metabolism of each organelle under the plant growth conditions. The expression level of GR in several organs of pea plants and under different stress conditions was investigated. The possible role of peroxisomal GR under abiotic stress conditions, such as cadmium toxicity, high light, darkness, high temperature, wounding and low temperature, is discussed.
首次纯化了存在于过氧化物酶体中的谷胱甘肽还原酶（GR；EC 1.6.4.2）同工酶，并通过免疫金电子显微镜报道了其在这些细胞器中的明确定位。该酶纯化了约21倍，比活性为9523单位mg(-1)蛋白质，每千克叶片获得44微克蛋白质的产量。过氧化物酶体GR的亚基大小为56 kDa，等电点为5.4。该酶可被针对豌豆（Pisum sativum）叶片总GR产生的多克隆抗体识别。GR在过氧化物酶体中的定位补充了叶绿体和线粒体中也存在GR同工酶的情况，并表明在植物生长条件下，该酶根据每个细胞器的代谢情况被多重靶向到不同的细胞区室。研究了豌豆植株几个器官中GR在不同胁迫条件下的表达水平。讨论了过氧化物酶体GR在非生物胁迫条件下，如镉毒性、高光、黑暗、高温、创伤和低温下可能发挥的作用。
