植物铁代谢及植物铁蛋白结构与功能研究进展

Progresses in plant iron metabolism and the structure and function of phytoferritin

铁在生命过程中起着很重要的作用,植物缺铁后叶绿素合成受阻而导致的黄化症状已成为世界性植物营养失调问题。与之相随,人类铁营养的缺乏也极为严重,因此研究植物铁代谢并且开发安全、天然、高效的补铁因子具有重要的意义。到目前为止,在已经发现的植物中,只有豆科类植物是将其种子中～90%的铁储藏在铁蛋白中,所以来源于豆科类植物的铁蛋白是一个理想的补铁资源。与动物铁蛋白相比,植物铁蛋白具有两个显著的特点:首先,植物铁蛋白在其N端具有一个独特的EP肽段;其次,植物铁蛋白只含有H型亚基,且有两种不同的H型亚基组成。主要阐述有关植物铁代谢及铁蛋白的结构、功能的最新研究进展。

Iron is an essential microelement for growth and development in human beings. Plant iron deficiency and iron deficiency anemia （IDA） are the most common and widespread nutritional disorder in the world, so it is of significant importance to elucidate the iron nutrition in p/ants and explore a safe and efficient functional factor for iron supplement. In legume seeds, more than 90% of iron is stored in the form of ferritin in amyloplasts. Therefore, phytoferritin from legume seeds is considered as a promising iron source to combat IDA. Compared to animal ferritin, phytoferritins exhibit two major distinctive features in structure. First, phytoferritin contains a specificextension peptide （EP） at the N-terminal while animal ferritin lacks. Second, only H-type sublanit has been identified in phytoferritin which is usually a heteropolymer consisting of two different subunits, H-1 and H-2, sharing about 80% amino acid sequence identity. This review focuses on recent progresses in iron metabolism of plants and the structure, function and nutrition ofphytoferritin.