Plant thioredoxins: the multiplicity conundrum

Thioredoxins are small proteins distinguished by the presence of a conserved dicysteine active site. In oxidized thioredoxin, the two cysteines form a disulfide bond that is targeted by the enzyme thioredoxin reductase. Together with an electron donor, thioredoxin and thioredoxin reductase form the 'thioredoxin system' that is present in all organisms. Thioredoxins participate in dithiol/disulfide exchange reactions with a large range of cellular substrates. Higher plants possess a very complex thioredoxin profile consisting of at least two different thioredoxin systems that contain distinct, multigenic thioredoxin classes which have different intracellular localizations. In this review we summarise the current state of knowledge regarding the function of plant thioredoxins representing all systems and classes. Received 30 October 2001; received after revision 13 December 2001; accepted 17 December 2001     

显著提高大肠杆菌中外源基因表达产物可溶性的双顺反子表达载体pNJUTRX-1

ＴｈｅｅｘｐｒｅｓｓｉｏｎｏｆｈｅｔｅｒｏｌｏｇｏｕｓｐｒｏｔｅｉｎｓｉｎＥｓｃｈｅｒｉｃｈｉａｃｏｌｉｈａｓｂｅｃｏｍｅａｓｔａｎｄａｒｄｔｅｃｈ ｎｉｑｕｅｉｎｍｏｌｅｃｕｌａｒｂｉｏｌｏｇｙ .Ｅ .ｃｏｌｉｅｘｐｒｅｓｓｉｏｎｓｙｓｔｅｍｓｈａｖｅｔｈｅａｄｖａｎｔａｇｅｓｏｆｐｒｏｄｕｃｔｉｏｎｅｃｏ ｎｏｍｉｃｓａｎｄｌｏｇｉｓｔｉｃｓ .ＴｈｅｓｅａｄｖａｎｔａｇｅｓｈａｖｅｍａｄｅＥ .ｃｏｌｉｅｘｐｒｅｓｓｉｏｎｓｙｓｔｅｍａｐｏｐｕｌａｒｃｈｏｉｃｅｆｏｒｔｈｅｐｒｏｄｕｃｔｉｏｎｏｆ…     

硫氧还蛋白还原酶结构分形研究

提出并应用改进的分形方法对硫氧还蛋白还原酶（TrxR）结构进行研究。建立了适用于TrxR的分形及数据处理方法。发现正常的TrxR的结构分维值约为1.33,氧化后结构分维值增大。提出了蛋白质结构分维值是表征蛋白质分子状态的重要特征之一的观点,并结合TrxR验证了该观点。提出了药物分子分维值应与靶酶的结构分维值相契合的观点,并结合以TrxR为靶点的药物研发实验验证了该观点。     

Plant glutaredoxins: still mysterious reducing systems

Glutaredoxins are ubiquitous oxidoreductases which are similar to thioredoxins and possess a typical glutathione-reducible CxxC or CxxS active site. We present here the current knowledge about these proteins in plants. At least 31 glutaredoxin genes are present in Arabidopsis thaliana, a value close to the thioredoxin gene number. Based essentially on active site sequences, a classification of these multiple genes is proposed. The specificity of the various apparently redundant forms within the glutaredoxin group or between glutaredoxin and thioredoxin can be analysed in terms of differential spatiotemporal expression of the genes, specificity vs. target proteins and mode of catalysis (glutathiolation/ deglutathiolation processes appear to be a specific function of glutaredoxin). Additional putative functions are proposed for plant glutaredoxins based on their targets in other organisms and in the light of the existence of hybrid proteins containing glutaredoxin modules in their N- or C-terminal part.Received 31 October 2003; received after revision 26 November 2003; accepted 4 December 2003     

硫氧还蛋白还原酶结构分形研究

提出并应用改进的分形方法对硫氧还蛋白还原酶(TrxR)结构进行研究。建立了适用于TrxR的分形及数据处理方法。发现正常的TrxR的结构分维值约为1.33,氧化后结构分维值增大。提出了蛋白质结构分维值是表征蛋白质分子状态的重要特征之一的观点,并结合TrxR验证了该观点。提出了药物分子分维值应与靶酶的结构分维值相契合的观点,并结合以TrxR为靶点的药物研发实验验证了该观点。     

心血管疾病中硫氧还蛋白相关的信号通路研究进展

硫氧还蛋白系统是体内重要的抗氧化系统之一,由硫氧还蛋白、硫氧还蛋白还原酶、硫氧还蛋白过氧化物酶及NADPH组成.硫氧还蛋白是细胞内重要的二硫键还原酶之一,在心血管疾病中发挥着重要的作用,这与其参与多种信号通路的转导过程密不可分.本文主要从心血管疾病中硫氧还蛋白相关的信号通路研究进展方面进行综述.     

Development and hormonal control of thioredoxin and the thioredoxin-reductase system in the rat liver during the perinatal period

Summary The development and hormonal regulation of thioredoxin and of the thioredoxin-reductase system were investigated during the perinatal period in rat liver. An immunological procedure was developed in order to quantify thioredoxin in fetal and neonatal hepatocytes. Both immunoreactive thioredoxin and thioredoxin-reductase activity appeared on day 16.5 of pregnancy. The level of immunoreactive thioredoxin increased during the late fetal period, and its level was the same 24 h after birth. Moreover, its development was not subjected to hormonal regulation by corticosteroids and glucagon. In contrast, thioredoxin-reductase activity increased 3 times during the late fetal period and presented a marked increase 24 h after birth. In the absence of glucocorticoids there was no increase in the level of thioredoxin reductase, while administration of hydrocortisone acetate and glucagon to fetuses prematurely evoked its activity. This study suggests that if thioredoxin acts physiologically, this activity is related to the state of reduction of the molecule rather than to the total concentration in the liver.     

大肠杆菌硫氧还蛋白thioredoxin基因的克隆及表达

以大肠杆菌XL1blue为模板，通过PCR技术扩增大肠杆菌硫氧还蛋白基因，并将目的基因分别连接到克隆载体pUC18和表达载体pTrcHisC上，构建重组质粒．重组质粒pTrcHisC-TRX在大肠杆菌中高效表达，最后利用固定化金属螫合亲和层析技术(IMAC)获得较纯的目的蛋白，为进一步研究硫氧还蛋白的功能及其应用提供了条件．     

青岛文昌鱼硫氧还蛋白基因的克隆及同源性分析

通过对文昌鱼神经胚cDNA文库进行测序 ,获得含文昌鱼硫氧还蛋白基因全部读框的cDNA序列 ,并演绎出对应的氨基酸序列 ,对其可编码蛋白进行了分析预测 ,还与多种脊椎动物和无脊椎动物中同种蛋白的同源性进行比较分析 .发现该蛋白具有典型的硫氧还蛋白活性部位 ,与脊椎动物硫氧还蛋白的同源性大于无脊椎动物 ,说明作为脊椎动物和无脊椎动物之间典型的过渡类型 ,文昌鱼在进化上更接近于脊椎动物 .